Just stumbled upon this thread. As I'm suddenly flying AirBaltic a lot these days (I was actually here to look for experiences with their FQTV program) I can actually provide a bit more information here.
The strictness of BT seems to be varying from airport to airport, or even from agent to agent. So far I haven't had any issues yet, but staff at the hub (RIX) has been the most strict so far. Staff in OSL can't care less, TLL doesn't seem to care either. VNO has been stricter a few times (no scale, just size). LGW also wanted to have a second look at my luggage but let me go through.
When it comes to a second item (handbag, laptop case): I haven't had any issue with that either. Usually (especially on almost fully booked aircraft) I only get the request to store that one under the seat in front of me. I've spotted a few people with two backpacks or a suitcase and a (small) backpack and it seems to have been no issue.
The same actually goes for the printing of the boarding passes. According to the rules you need to do this at home with a few of their tickets (those hand luggage only, no frills ones). So far only staff in VNO gave any trouble when I hadn't done that. Even in RIX staff at the check in and transfer center were willing to help me (without any additional costs).