he most damgerous thing about missions is when the next wave spawns - becasue they'll choose a target, whihc won't always be your 'tank', and stick to it regardless. There's no aggression mechanics for NPCs in missions they just choose a target and pursue it until it's gone.

Therefore, every ship thats going to be in your gang needs to be able to tank the whole mission - including your salvage ship. Anything that can't tank needs to stay out of the mission space until it's cleared.

Regarding key repeating I've been working on this recently using ISBoxer. The crucial point is that 'hold' needs to be on for keymaps: http://isboxer.com/forum/viewtopic.php?f=8&t=1128

There's a guide on the ISBoxer forums too, although it was written before the new keyboard shortcuts were introduced: http://isboxer.com/forum/viewtopic.php?f=8&t=878

Using the keyboard to control multiple toons really works well. You need to set up your overview for missions to filter it down to just enemy ships (or even single enemy ship classes) so that target selection is easy. EVE are introducing more default overview settings soon as well. Using a fleet means that your 'main' toon can warp the other toons around whihc is the only form of 'follow' there is.

EVE can be very boring to play, from one point of view it's all about PVP and every other activity is there to support PVP, from another point of view it's about making the most ISK and playing for free, from yet another it's all about how many people you can grief. That's why they call it a 'sandbox' game.

Don't forget there's a guide sticky right here: http://www.dual-boxing.com/showthread.php?t=21126