Hi, glad to have first-hand info.
FYI the Polish OOB has been redone with Polish assistance already.
1) No idea, probably just inconsistencies as different OOBs were done by different persons from various sources. Also, as I have seen, hard data on the Spike series has been very hard to come by. 160 seems a bit over the top, but I wouldn't have ruled out 120 or similar.
2) You'll have to look harder in the archives for confirmation, but I heard from the devs that HEAT TA-ATGMs are considered by the game as having advanced tandem warheads with regard to ERA resistance. AFAIK most top-attack missiles these days (bar EFP weapons that I don't model as HEAT personally) have tandem warheads as well. No that there's that many of them around yet, but you get the idea.