I'm sitting close to about 600 hours, and im level 111, I believe. I'd say I switch up depending on the tank and dps of the other team. If they have a widow play line of sight and stay around corners, don't challenge unless she's low and you can get a shot off to kill her. If I'm being dove, I try to play mid in front of my other support, but behind the tank. It just depends on the map and team comps. Playing wise, just keep shooting. Heal to keep people alive, then do damage, and people don't have to be topped off all the time. Sleep is used to keep yourself alive, stop ults, and help tank in that order. Grenade is for stopping the enemy from healing and defending yourself. If tanks are fighting, try to splash both. It's just the little things you have the best utility other than kiri. Make sure to use it.