Hey! I did all my fATPL training with airBaltic and have started the TR on the A220 recently, so I'm sure I can give you some insights on what's going on and maybe address some of your concerns.
The DA42 sim is quite common - the reason is honestly fairly simple - mainly the fact that the A220 is just always completely booked out. There is only one A220 simulator currently, many MCC guys and TR guys are making some use of it and it's running 24/7, even during nighttime, so there is hardly any time for applicants to go in there and do their assessment. On the other hand, the DA42 sim is currently free as most guys are either still in their VFR or theory phases, so it has a lot more capacity. Therefore yes - it's all good and I've met a bunch of candidates who had their assessment in the DA42, even highly experienced people with hours well into the 1000s.
About the TR on the A220 - If I'm not mistaken, it's free. Not some loan by airBaltic or anything that you pay off later, no, it's fully paid by airBaltic and you'll have no additional costs besides living and all that stuff, of course.
The management interview is pretty much just what it says - an interview with the management, after passing all other stages successfully, to have a last clear impression of you, asking you a bunch of questions about your life, your flying experience and all that good stuff. Nothing to really stress about, most people say that they found the atmosphere very pleasant and friendly.
Hope I could help you out a bit, good luck!
