No worries, well not completely, there's a pilot involved
The most dangerous part of the RV is between your ears.
ENGINE MOUNT, MINES BIGGER THAN YOURS
If Cessna wants to use bigger tubes for an engine mount, fine, but what is the wall thickness? Was it a Continental engine cradle mount? Engineering is science, art and commerce. There is no telling why you had the impression Cessna's engine mount was more beefy? I can tell you the engine mount on a RV is built like a brick outhouse. I know of no real issues with the RV engine mounts. There have been cracks however, but that is not common with any engine mount. There's a FAA publication for mechanics of critical service reports from other mechanics submit on all kinds of aircraft all over the country and world. In some cases RV's show up, but it's mostly your typical Beech, Cessna, Piper and larger commercial aircraft. Many reports involve potentially serious cracks in control systems and even things like engine mounts. I can tell you all planes have issues from time to time with their engine mounts, but by all means during annual and every time you have your RV cowl off, look at the engine mount. If you don't know how to do inspections or look for cracks, ask a A&P to show you. Pay special attention to the welds and use magnification and good light. Just so you know there is lots of redundancy on the engine mount and one crack will not cause you to lose the whole engine. If you look at more engine mounts on other aircraft, they can look real weak. The RV engine mount looks very strong to me.
I've been messing around with RV's for 18 years and have a back ground in aerospace structure. RV's are some what overbuilt. Certainly the engine mount is not an issue. I've also had the pleasure of being a CFI in my early flying career, flying probably +20 different models of GA aircraft from 6 or more manufactures. I can say the RV strength is not in question.
Let me tell you a story. Ladies have that sixth sense, God bless them. This one lady flew a lot in different GA planes, like Cessna's with her husband, albeit as a white knuckled passenger. When she transitioned to the RV her husband built, she loved it!
It just felt more solid, especially in turbulence, and she could see more. From a pilot stand point sloppy cable controls, sounds of airframe oil canning (clunk-clunk) and doors popping open from airframe flexing does not build confidence. I have experienced all those scary things in factory planes, but not RV's.
LIGHT DUTY?
There are parts on the RV that are not as robust as they could be, but they where designed that way intentionally for performance. The gear comes to mind. It's designed for the purpose landing and taking off, not smashing. It works perfectly but not OVER BUILT. A C-152 has stronger gear. Still the RV when abused do their job and may have an advantage of not causing greater damage to the plane. I've heard about bent RV gear from landing accidents that are replaced successfully without other airframe damage. A hard landing in a C-152 or C-172 tends to bend and wrinkle firewalls; They are not immune from a ham fisted pilot.
Another light duty items may be the canopy. The tip up is there to get caught in the breeze when open. The slider canopy is more resistant to wind when open on the ground, but its not like the door on your car. It's a design trade off for the beauty of the bubble canopy view.
Regarding the canopy, RV's can dig-in a flip, especially trikes (sorry that's my opinion) when landed off-field on soft unprepared surfaces. The bubble canopy we love, makes egress harder if you flip upside down. Every RV'er should have safety or emergency canopy "tools" to cut, break and dig their way out if they do flip. I don't worry about it, but the type of canopy we have has pros and cons. I have seen my share of Cessna's on their backs as well, but the doors should be easier to get out.
FAILURES?
Have there been inflight airframe failures? Yes, a few RV-3 wings have come off, most happened in the early 80's. There where almost no failures for a long time, than the last two I know of where in 1995/98. All of the accidents where either from builder construction flaws (mostly with early RV-3's) and/or pilot error exceeding G limitations. The RV-3 did go through several wing mods early on. which of course improved the bred and made it easier for builders to construct properly. The original design was adequate but Van basically add even more margin. Think about this, many factory planes rely on one bolt to hold the wing on. I've heard of RV's flying WITHOUT THE REAR SPAR BOLT INSTALLED. That's no rumor.
Of course there was the tragic prototype RV-8 wing failure in California. That was also determined to be an overload beyond the max allowed. The RV-4 by the way gets even lighter stick forces in pitch with a rear passenger. I assume the RV-8 is the same. This is what probably contributed to doom the RV-8 prototype: two big guys (over gross), friends who knew each other, one never flew a RV, the other pilots guard was down due to familiarity with the co-pilot and lighter controls with a rear passengers. Both had ag-crop dusting experience in heavy planes which have much higher control forces.
PILOT RESPONSIBILITY
With a fast high powered plane with light controls pulling wings off is possible. Just dive near Vne, pull as hard as you can, the wings will come off. I have seen airshow videos of serious aerobatic planes folding wings. Not pretty but it happens. Keep in mind a RV has an ultimate Pos G of 9, limit or operating G of 6.0........ 99.9% of normal "Gentleman's Aerobatics" can be done at or around 3 G. At 3 G's you have a factor of 3 to failure. Ultimate means the plane will not fail but may suffer permanent deformation. Limit load (6G's) can be experienced with out permanent damage. There have been more than one RV that went past 9 G's and lived, albeit in some cases with airframe wrinkles!
You can pull the wings off a RV or any plane, Yep.
Cessna's benifit from being slow. The dynamic forces at 120 mph are much lower than 200 mph by near a factor of 3 times. Point a RV nose down and watch the airspeed wind up; low drag, high power, light controls is fun but carries responsibility. Considering the excellent safety record of the RV, its clear that that average pilots can fly RV's with little problems. Like I first said, most the danger is between the ears.
How many factory airframes have broke-up in flight? Beech Bonanzas, especially V-tails had a bad reputation for coming down in pieces. Most of it was pilots flying too fast or losing control in IMC conditions. Like the RV-3 wing, Beech re-re-designed the V-tail attachment to make it even stronger. Also like the Bonanza it's a high performance plane with low drag.
SUPER PILOTS NOT NEEDED, JUST SMART ONES
A Cessna is a truck and a RV is a racing sports car. It easy to get in trouble with a hot overpowered sports car, but trucks also crash. However in the right hands a sports car handles better, stops better and accelerates better and can be safer than a big truck, which can't turn or stop easily. I'd rather fly a RV than a little Cessna or Piper any day. One reason is greater performance, which if used properly gives greater safety margin. The ability to use less runway and climb faster to a safe altitude is a real plus.
Yes, you have to be careful not to pull the wings off any plane, especially high performance planes like RV's with lighter controls, but than again RV's have aerobatic strength airframes, verses a normal and utility category Cessna's.