There are plans to change the crafting system.
We will need blueprints to craft.
If that means we can craft everything if we have the blueprint for it, it would remove the need for crafter alts.
Still you'll need 2nd prof for that. As I heard tier3 items will require prof2+blueprint, if you're going to do PvP with your science and repair skills, then yes, you don't need crafting alt ;p
I think mercs should be able to craft for you, actually "mercs" means followers like Vic or Myron, so if you have 3 CH, it means you may take 1 follower at a time with you. If you're crafter you'll take combat merc, if you're combat character, then you'll take SGer or Armorer or BGer or EWer merc, who has lower combat skills than combat merc, but gives you profession ability when he's following you and near you. Also you'll ignore skill requirements for crafting of merc's profession items, if you lack them and skill requirements of all tier0 items. Prof1 mercs should be cheap and weak in combat, Prof2 mercs should be more expensive and a bit weaker than normal combat merc.