There shouldn't be any adjustments made for players who haven't played all season. The point is to vote for the best player of the season, so naturally, the guys that play more games should be more entitled to get that award. As Rich said, the system rewards consistency. If a bolter comes in and plays one good game, gets a 3 from everyone but is injured for the rest of the season he hardly deserves to be the player of the year based on one high ranking game. Same thing applies to Tai'ai. To be fair though, assuming he doesn't get injured, he'll play more than enough games to be competitive, and could even win it with Rapira on the sidelines.
As for a spreadsheet, you can attach files to a post and .xls is a supported format, so you'll be sweet to just attach the entire thing to a post at the end of the season or whenever you want to. Would be interesting to see.