Just one man's opinion but here goes:
Why would you use a relay if a suitable switch is readily available? It's not difficult to find 10 and 15 amp switches. In fact, I would be surprised if any switch you own (other than maybe the tiny little micro switches) are rated for any less than 10 amps, and they're probably more.
If a switch is rated at 10 amps, it's not marginal at 10 amps...it's perfectly happy at 10 amps. If that weren't the case, it'd be rated at 9 amps, or 8 amps.
So for example, do you put your lights at home on an industrial relay because you don't like running 110 Volts/15 amps through a small switch? The answer is no because the switch is designed for the job.
I wouldn't use a relay anywhere except if:
a) I wanted to mount a micro switch somewhere to control something that was more than, say, 5 or 10 amps
b) it was more than, say, 10 or 15 amps and I couldn't find a reasonably priced switch, with the proper rating, that matched everything else in the panel
It's your plane and your comfort level and you should always do what you think best. I just think that with a little more information your comfort level will increase with running electrical stuff right up to it's rated limit. I wouldn't have any problem running a 10amp rated switch right up to 10 amps....maybe 9.9. .1 amps for the wife and kids....
![Big grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)