Recently got my 3rd guitar. I'm still pretty much a novice (a bass player of 10+ years who converted last year). I decided to go for a schecter with active PU's (sd blackouts i believe), bought online so didn't get to try before i buy.

Ive never played a guitar with active pu's before. All the 'acoustic' sounds are coming through to the amp on this one, very loud string scratching sounds just from resting my index when changing chords etc. I'm getting an audible thump when just lightly placing my fingers on the strings to rest and now my palm muting technique sounds like crap because i get a slight background noise from friction near the bridge and higher strings. All the things i could play & record before i no longer can.

I'm not sure if this is a case of me having bad technique or i need to adjust something. Turning the PU volume down just makes the tone sound so flat and upping the noise gate to the level to cut these sounds out also causes problems.

My other guitars are a beat up 80's strat and a gibson sg with p90's (which people said are normally 'hot' yet on high gain i never had any issues with technique). Its totally demoralized me as a player as i sound like a complete beginner trying to play on this (at least when its plugged into an amp). I'm considering just selling it and getting another passive.
Sounds like its a technique issue - humbuckers in general are higher output than single coils and P90s, so that is going to up the sound pickup on finger drags etc, SD blackouts are high output humbuckers amplifying the issues even more, and high gain settings on your amp are going to accentuate further these things.

I would say keep the guitar and work on your technique.