Stacking Resident bonuses, and other intricacies?

Hi, so I'm fairly early-to-mid game currently. I restarted 5 times, once due to loss of world and backup somehow, as I learned more and wanted to start doing things earlier in the character, etc...

I have learned most of the basics (hopefully but probably not =D), but there's some things I am still not 100% on, and i couldn't find answers by Googling, so I was wondering -

1) The Pioneer resident trait - how much of a bonus is this, and does having multiple resident's with it work to stack, possibly with diminishing returns on amount of them? it doesn't show as fixed value or affected by bed/affinity/etc... (like say blacksmith with a %)? I assume it is affected by bonuses, and it's a very small multiplier? Is this ever worth having to boost the slow crawl on the Hearthstone experience gain, or just keep chucking shipments is always best and Pioneer isn't really needed?

2) Are land traits random? If I claim my next land, is it rolled before/after claiming it? Is there an optimal location for maxing residents and efficiency bonuses from land traits? So in essence, is there a list somewhere showing really good land claims?

3) Is melee worth pursuing into late game? I am just about to unlock advanced Nefias with the license, and I have noticed a slow decline in melee effectiveness, despite training my weapon, Tactics, Eye of Mind, weapon, getting a workshop weapon (the 70% pen one for now). Magic seems to be more effective and/or have a higher effective ceiling currently, are utilizing de-buffs more important as bosses get harder too?

4) Is there a way to affect level gain for spells? Is it just higher magic/Will/Casting levels? Or unaffected, and just requires more casts per level forever?

5) Barring resistances based on type of Monster, are there generally accepted best "damaging" spells, or does this just depend on how high you level something? My Poison and Shadow Arrows are getting fairly high, and I've diverged into most other domains just for variety and to best resistances, but will they eventually be no good no matter how high i level the 'basic' starter spells?

6) I've read some posts about breeding an "ultimate" pet - is this necessary for highest Nefia, or breeding pets of at least decent quality required to do higher stuff in general? Is there a guide on doing this, and what I need to breed together?

7) Just about to get my fourth God recruit, I know 3 in my active party will fight. Is this still the case if I Host the cat, and have 2 following normally?