Can I pick up weapons/gadgets and still receive professional boxer?

[Rocky McRockerson]

Since games often do things differently, I don't know if even picking up things will nullify the achievement. I'd like to get the unique ones to unlock them but I don't wanna potentially lose the achievement.

[Rocky McRockerson]

Also, are you allowed to use bottles/cans?

[Iteration]

If that's still relevant, you're allowed to pick weapons as long as you don't fire, for sure. I picked up a couple weapons lying on the floor by mistake. You can drop them using G to make sure you never fire.
I guess gadgets are the same: you can pick them up, but not use them.

I don't know about meleeing with a weapon though.

For cans/bottles, I didn't use them, but I've seen people comment that it disables the achievement. Same for door slam kills. Enemy friendly fire is apparently OK though.

[MasterStudioCZ]

No clue if it's still going to be helpful, but I just finished both Hippy and Professional Boxer achievements in a single normal run and I can say that picking up and throwing bottles and cans does not nullify the latter achievement.