Thats a non-issue. Ill be 38 in Dec and Ive not run into that issue. You may be surprised how many of us geezers are playing WoW. Of course you run into the occasional tard but you can "ignore" them. Most of the game can be soloed anyway with the exception of instances.
When grouped for instances most people arent in a hurry. As a mage I frequently have to stop to eat/drink and its never a problem.
You will be golden with a cable modem.
Definately go on a "normal" server. There you cant be ganked and trust me, nobody chats "in character" there. Its darn near the perfect game for me. Epic powers, beautiful world, fluid gameplay, unnumeral weapons/armors/stuff to play with, character customization, interesting quests, etc... Its literally the reason I cant be arsed to play my copy of NWN2. With my limited gaming time, why waste time on a flaming POS when I could play my beloved WoW?