Return of Reckoning

Now with x2 coming i am planning to level some characters to 16. And i was planning to make them profession makers. And my main also

I am planning to level:
Slayer
Runepriest
Ironbraker

My main is engineer.

Now, to start professions, i saw on wiki this:

Apothecary - Cultivating and Buchering
Talisman making - Salvaging and Scavenging.

Here will be the paths i will follow for all my chars:

Irobreaker - SCs only, not a single RvR or PvE
Runepriest- RvR only, not a single SC or PVE
Slayer - PvE only, not a single RvR or SC.
Engineer - everything PvE and PvP

Now the real question comes: how should i train them, regarding of the above?

Slayer clearly Scavenging, dungeons are a great place to scavenge since since certain purple fragments (like armor) only drop from champion+ mobs.
Engi for Butchering, I often see engies at my usual armor/blast pot farming place and they do fine.
Runi for Salvaging, after a while you have a lot of vanq medals you don't need. You can trade them for vanq armor and salvage them for purple fragments.
IB for cultivating since its left and can easily be done during SCs if you use the addon Miracle Grow Remix.

Perfect! Thank you very much! I will do accordingly!