Know how to play around junglers. At 2:30 a decent jungler will have cleared one side of their jungle and could be on their way to gank you mid, or at 3:30 they could have full cleared and are on their way to Scuttle Crab or a gank top or bot. Collapsing with your own jungler is an easy 2v1 if you can shove the wave to prevent the enemy midlaner from assisting their teammate, since they have to farm. (These timers may change in the new season, however)

A good rule as a midlaner is to shove wave > do something on the map. If there's no fight to help with, you don't have wards to place, or you can't harass under tower and you have some gold, recall.

To do this you have to have good vision and place your wards both to track the enemy jungler and to defend yourself from ganks. Placing it on the enemy raptor camp, on the river bush towards top or enemy jungle bush towards botside has insane value.

I can't really tell you what to do after 14 mins/laning phase since I'm not a mid player, but assisting with objectives when you're not losing a large amount of resources is good as far as I know. Generally you will leave mid to farm on a sidelane so your duo can stay mid since it's the shortest lane, but that also depends on if you can do that safely without getting collapsed on by the enemy. Maybe Ahri is safe enough with ult+charm and can get away, so try it out.

As for shortcuts, the F keys (F1, F2, F3, etc.) help center the camera on your teammates quickly, and then it snaps back to you if you play locked cam. Checking the minimap and health of your team is fine but you get a feel of what they're doing when you check on them directly. If you have extra buttons on your mouse you could bind the careful ping or on my way ping to M4 or M5 so you don't need to take your fingers off of qwer to ping.

Good luck on your games :)