Most of the answer = common sense on the day
Size is short...never seen any rules but have a feeling you will gte told off with a full size tripod and never seen one used myself
You pull the net back to see how far it can go and put your gear a little further back..
Your controllers have channels ..the games i go to theres rarely more then a couple behing goals if that so make sure not on same channel.. personally i ahvent seen anyone witht the same equipemnt as mine so shouldnt clash
usable behind the goal shots are rare so personally i leave it there and if theers a goal and i think it might be a good one i might go grab the camera.. depends on circumstances.. if i am sat wiht other photogrpahers all rushing to get the shot away then leave until later.. if on a commision leave until later.... most of time look at HT and FT but if you think you got a great shot then go grab the camera
PS I onlt use behind the goals camera now and then.. not every match.. inf act rare as league two not much room most grounds ..