Given the number of messing around runs I've done. I usually bypass Gale or other companions, if the goal is not not include them.
They all magically know/complain about things you do, even if they are in camp. - Something that honestly annoys me to no end. If companion A who's with Custom B can't see to complain... how does companion C and D who isn't even in the party at the moment get a chance to dislike a thing?
As for the spoilers to other games you've posted (very bad form, I may add) ... it is an earned trope that Wizards, Rogues and Warlocks can't be trusted. Ever. Exceptions exist, obviously. But when the %percent chance is above 60; you come to expect it.
My two main current planned games for version 1 (release) ... I will likely drag Gale along purely because I'll need a wizard. It will greatly depend on what we've been told, are the missing "good" companions, will be in terms of race and class.
The most likely outcome will be the flat out murder of Gale, pushed into a river... and his very rare loot kept for other uses. The plot attached to him can deal with the local area... I don't intend to remain either way.
and if he's in my party. I do not look forward to having to deal with what has been currently portrayed as a drug addict. I don't suffer them in real life. It will be annoying to deal with in game.