I have good reason to suspect that the answer is "no".
I've been up to plenty of mischief since having an account unfrozen, and nothing seems to have raised alarms. I had an especially concerning issue involving another player recently, and despite having to make contact with the Neopets team to settle the issue, I was able to have my problem addressed without drawing their attention to the various items and pets that had circulated through my account.
Personally, I have a ritual for doing something dangerous. If I'm transferring a pet or item, I lay low for a few days. No trades, no Neoboard conversations, no auctions, no score sending. It gives me the comfort of feeling like I'm avoiding the prying eyes of fellow players.