I doubt you will fry anything with the levels from your A4. Nothing is impossible tho, but I doubt it.

If you want to track through a hardware compressor for sound refinement reasons it definitely makes a difference. But you’ll have to drop a lot of money for a really decent compressor to hear a significant difference over plugins.

And of course you won’t be able to use it with Overbridge so you’ll have to record stuff track by track.