Kyle,
I think the guys covered the safety of the acid wash.
As far as the compound step, I don't think that is one to be skipped if you want a long lasting shine. I only needed to sand areas which were scratched. Rounding off the sharp edges of scratch help to make them disappear from a few feet away.
Compounding will take the finish from dull to shiny. If you stop there it may look good but will still have fine swirls. Microscopically the surface is still rough and more surface is exposed to UV rays and the shine won't last.
The polish step removes the swirls and smooth's the finish. The waxing protects the finish.
Now, I am not an expert. I am just regurgitating what I learned from Maine Sail's article.
I believe the answer to whether the compound step is required is yes. If the detailer is skipping that step I would be worried he is using a polish that contains silicone which gives the gel coat a fast but false shine that won't last the season despite a good wax.
Like I said, I followed Maine Sail's steps, except for the acid wash, the spring of 2013 and put on 3 coats of 3M wax. Spring of 2014 I gave it a good soap wash and another couple of coats of 3M wax. Still getting compliments.
There is a guy with a O'day 26 that ends up near me for the winter. He uses a buffer and one step cleaner & wax. He does his boat fall and spring and is happy with it.
I guess I am revising what I said in the first answer.
If you can wax the boat yourself, then the $800 job, which is probably a complete job, could last several years with you waxing it a couple of times a year.
If you can't wax it yourself, maybe the once or twice a year $285 quickie job is the way to go.
As far as damaging the gel coat, I don't think either method is better or worse but it makes sense that the more you compound/polish the gel coat, the thinner it will get.
Of course, this is just my opinion and YMMV.
