I agree with the others that think some extra MGTW is called for. How much is debatable. 1500lb would allow more "antique" LSA such as the later model Ercoupes, Cessna 140s, some Citabria 7ECA. 1650 is needed to include all 150 and 152 models.
If you increased the MGTW, you would (a) allow more existing certified airplanes to fly as LSA and (b) allow for sturdier new LSA. Let me give you an example: Consider new all-metal designs like the RV-12, RANS S-19 and, yes, even the Cessna Skycatcher / 162.
Much has been made of the porky empty weight of the RANS and Cessna, leaving, well, not a lot of useful load. The RANS went from the O-200 to the Rotax because of weight - it was pushing 870 empty with the O-200. Increasing the MGTW would allow O-200/O-233/O-235 powered LSA while still having a decent cabin load. My definition of "decent" is 400lb of crew and baggage with 4 hours of fuel on board (3+1 reserve). At 5.5 gph, that translates into 532 lb payload. With an empty weight of 850, that's 1,400 MGTW. I'm lucky enough to have a LSA with light empty weight and lots of payload (712 and 603 lb/ respectively), but there are clearly sacrifices that have been made to keep weight down at the expense of durability.
The 120kt limit .... As much as I'd like to have it increased, I can see why the limit is there. You could make a case for slightly more speed or a Hp-based limit, but you have to draw the line somewhere. 120kt is about 172 performance, and given the relaxed requirements of the SP ticket, that seems to make sense. Hp limits are problematic with very clean airframes, e.g., the Rutan Quickie, which would probably do 145kt on 100Hp.
In-flight adjust props don't make that much sense to me, given the speed restriction. The rules are very unclear on what kind of adjustment can be made on ground-adjust props and how manufacturers and pilots can have some assurance that they are in compliance with the 120kt ISA/SL limit.
Unpressurized, 2-place cabins are Ok, as is the 45kt stall speed. Ditto the fixed gear.
On the Sport Pilot side, the FAA has proposed a number of changes that make sense, e.g., eliminating the requirement to carry a logbook with all applicable endorsements. The proposed change in maximum altitude restrictions from 10k MSL to 10k MSL or 2k AGL, whichever is higher, is helpful, but flying 2000 feet over a 9k mountain pass doesn't strike me as a high level of safety. 2,500 AGL would be slightly better and then harmonize it with the requirements for oxygen, which (IIRC) begin at 12.5k. Yes, lots of LSA aren't going to perform well at 12,500 (or even get there!) but some will and do.
TODR
