This idea wont reduce alts at all, Id say the opposite. People will start making easy-levelled alts in order to lvl up other characters.
the only way to reduce alts is to registar an account rather than a characterin that account there would be a number of slots caping the number of characters..All players caught with more than one account per ip would be banned, simple
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,