For accepting quests, get twoboxtoolkit addon. You get most quests on your main, share them and all other characters will auto-accept....only quests it wont work on are those where the npc then gives you an item as well as the quest.

For handing in quests, yes you have to manually click on the npc but with the window focus code now in keyclone (and god that saved me when I went to Vista Rob, well done there) to remove one click to focus the window and twoboxtoolkit automagically clicking through the gossip screens after you right click on the npc to hand in, I dont really see the big hassle.

And yes, for looting on collection quests the focus follows option is again a godsend...the only other thing to remember is to leave looting with your main until last so you can either still see the sparklies for ground loot or know that once you get the message they have completed the quest then all your others will have as well. Questannouncer is also a great addon for this purpose as you will see your other characters progress pop-up on your main screen and party chat to tell when they have finished as well.