(1) is pro-choice
Source? There are some old news stories that say this (without sourcing it), and a contemporaneous interview with the head of a national right-to-life organization contradicts those reports, saying Thompson is solidly pro-life. His Senate voting record on pro-life issues is 100%, minus some votes on campaign finance reform, which isn't technically a pro-life issue anyway.
(2) favors the McCain-Feingold bipartisan "Campaign Finance Reform" act
Use the correct tense -- he favored it at the time, but has gone on record admitting it was a mistake and that it should be tossed in favor of something better, potentially even going with "no limits, full and immediate disclosure", a very conservative concept.
3) supported keeping Bill Clinton in office after he was impeached
Thompson voted for conviction on the most serious charge against Clinton. He did not believe the lesser charges were sufficiently proven (more likely due to Frist's ineptitude at handling the whole situation than Thompson giving Clinton a "pass").
(4) supports affirmative action
This is the only potentially worrisome item on your list, and his record appears spotty. In some cases, he voted against creating "set-asides", but in others, he voted to continue existing ones. "Affirmative action" is also a loaded term, it can mean anything from making good faith efforts to hire based solely on qualifications ("color-blind") to quotas and set-asides.
(2) I'm glad he changed his mind. Did he ever make any effort to correct his mistake? We don't need any more flip-floppers on this issue.