Hello Mac,
player load tells if player is able to play transactions on time. If it's over 100% it means that some transactions are delayed because player runs on full capacity and they have to wait. How many transactions do you have assigned to single player? We have seen few cases when relatively simple transaction was stuck on player for long time and it occupied playback capacity. WPM tries to ensure that page is fully loaded before it moves on. If there is for example periodic AJAX request on the page which pings server every few seconds then WPM can wait up to 30 seconds due to that periodic request. Having this in multiple transactions can easily overload player. There are ways how handle this but for that we need to get more information. Support case is the best bet.
Player load can be also related to your third issue. If a transaction is not played for more than 2x its frequency (if you have transaction with 5 min frequency and it's not played for more than 10 minutes) then it goes to unknown state. Solving player load issue should solve also transaction unknowns.