Transitioning to FBA from FBM

Looking for insight on a couple of issues. We have sold products in the $10 range for 8 years via FBM. Recently, the Chinese sellers have moved into our industry and just dominate first page search results. Almost all of their products are Prime. While we used to always have a few of our products near the top of search results, not anymore. We figure the only way to compete is to move to FBA.After some cost analysis, it looks like we will just need to sell a couple more units, per SKU, per month to at least break even as far as the net profit we have been making.
We sell about 1000 units per month, with our top SKU, and its variations, getting about 100 of those sales. 360 different SKU’s in all. We used a median-selling SKU for our analysis, if that matters.
First, any idea what type of percentage of increase we may be looking at in terms of units sold?Second, and this is one of the big apprehensions we have in moving to FBA, our products are handmade but we have chosen not to sell in handmade. IMO, they are very well done(been making them for 15 years) and rarely receive complaints. Our worry is that someone analyzing any returns will realize they are handmade and will “tell” on us, getting our ASIN’s removed. Anyone with any insight on the possibilities of this?
Also, we didn’t need brand labeled packaging when we got into Brand Registry. Our items will be shipped into FBA using plain brown boxes labeled with the SKU stickers Amazon provided. Any possibility of not having branded packaging biting us?

I realize there’s always a risk of sorts. Just want to know if I’m being to paranoid about those risks.

Thanks!