hey @nuthan,
sorry for the delayed response.
In terms of trading AFIT tokens, the listing of AFIT tokens on Steem-engine was part of the "ISO" (Initial Steem Offering) event we conducted a month ago, not intended to open up large scale trading.
Real trading of AFIT tokens will happen once we perform our intended IEOs.

For the exchange of AFIT tokens for votes, the rewards you receive, considering the valuation of AFIT tokens at $0.036 cents, takes into consideration the beneficiary rewards. So you actually get an upvote approx equal to the amount at 0.036$ disregarding the beneficiary rewards.

The reason we decided to consider only actifit report cards is for several reasons, including incentivizing more activity, but also avoiding any potential non-actifit spammy posts (our team reviews actifit posts, and bans abusers, we cannot do that on the whole of Steem).

For the 40 AFIT tokens you used, if in 2 weeks the vote did not take place, you actually get refunded your tokens back.

For the score posting via desktop, that is not possible at the moment. Your activity tracking is done via your phone (or fitbit), so you need your phone and actifit app to send at least your activity score. We can look at improvements and alternatives to this down the road.