Videos will not install adware, but some of the offers will.
There is no such thing as bidding bots, how ridiculous would that be.

If you want a bidding war sell your guys early in the season during the day. I am usually happy to get near market value, so I don't bother with when I sell them, but it can make quite a difference. Usually I have found that STs and triple roles are most likely to cause a stir on the market, all my triple role guys sell for good money.
I have never went to my last token for a player.