Hey Linny,
thank you for all the thoughtful questions!
Question 1:
Seems you got it all figured out, except for User Rank, you missed 2 factors:
25% for profile - User Rank (Delegation + Actifit tokens + Number of total rewarded posts + Number of Recent Rewarded posts in last 10 days)
Question 2:
Upvotes to your posts will actually receive AFIT tokens from a pool of up to 20 AFIT tokens, according to their share based on Steem's voting system, so if they vote late, or have a very small upvote, their share will be quite small. So if you have a post with 1 SBD or higher before Actifit upvotes, the person who upvoted it the earliest and the most will get the bulk value of the 20 tokens, all according to Steem reward distribution system. If your post has several upvotes, and all are of low/equal value and around close times, they will all have "almost equal" distribution of tokens. Again the judge of that will be Steem approach to reward distribution. If the post does not reach 1 SBD, say it reached 0.5 SBD, then instead of 20 AFIT tokens available, only 10 will be available.
Question 3:
The Actifit bot upvotes every time it reaches 100%, this is currently occurring at around 23:00 GMT. While this timing changes daily due to upvote amount cast, yet we advise anyone to check on that if they like to see when the next round occurs.
In the current rewarding mechanism, any post that is less than 30 mins age is left for the next day's round to give it chance for more exposure, we are looking at increasing this to 2, 4, or even 12 hours, as we see how the voting progresses out.

Hope this answers all your questions :)