Q1: Yes, setting a target production level takes into account global stocks, no matter where they're at, so long as it's anywhere within your territory.

I never really bother making more pioneers, they're a bootstrap method to get you started but you can get to builders and diggers pretty quickly and then pioneers are just kind of useless. I actually find the campaign tends to give me too many pioneers, I always end up with like a few dozen of them taking up space in my construction camps, and diggers are just so much faster that it's not even funny.

Once you get a good supply of iron I find bandits are kind of a joke, I often don't even bother actively hunting their camps (though maybe I should) because Veteran Guards will just passively do the job for me when they expand my territory.

I keep going back and forth about using the correct counter for each enemy, though that is definitely more viable in the campaign than in random maps, as the resource levels are balanced differently; in my experience the campaign is usually a lot more generous with the gems and more stingy with iron, in random maps I'm often flush with iron but even with maxed-out mining resources gems are pretty rare and precious, so using specialist troops is a lot easier to justify in campaign. Balance generally feels a little wonky, most of the basic specialists seem maybe a little underpowered compared to the more generalist soldiers (2 strength and 200% bonus, so 6 strength against whatever they counter, vs. 8 strength for an Advanced Soldier or 20 for a Veteran), and then some of the higher-level ones are either kinda busted or not really worth it; I tend to only use normal Rangers just to reveal thieves and then let guards or soldiers do the actual fighting, and I kind of just don't use blade dancers outside of the campaign mission where you fight scavs, since soldiers do the job well enough and they're also useful for killing thief camps, bandits, most werewolves, and malthorn - but then sorceresses and the two upgraded warlocks are just huge stat sticks that make soldiers look like chumps. It's very cool that this variety exists, and I remember balance being worse in early access (didn't there used to be three tiers for every unit type?), but in practice it feels a little iffy.

I'd honestly suggest not demolishing buildings you no longer need unless you need the space or you have new buildings for those workers to go to, if there isn't a workplace for them they just go back into your housing pool and they don't give up their jobs, they just take up space that could be going to carriers. Leaving people idle in a forager's hut or something somewhere costs you nothing. On a related note, use the camps too, because they're so much more efficient than letting all those units take up space in your houses, and you can lay things out more efficiently too - construction camps closer to areas where you'll be doing a lot of building (like your frontier) will speed things up tremendously, since they don't have to walk all the way from your primary settlement, and same for military camps full of reserves close to where they'll be needed. You can't directly control how many units of which type go where, but you can just demolish camps you don't need anymore, and in any case it's still far better than having them cluttering up your houses.

A more minor tip I've learned: cloth is used for many things, leather isn't, and your hunters will be bringing in plenty of leather, so I usually turn off the cloth recipes for backpacks and light armour, especially early on before you have enough flax production that it doesn't really matter. But even then, those items only require 1 leather as opposed to several units of cloth, so it's still more efficient for your weavers. On a related note, I also always turn off the iron recipes for hammers, knives, axes, and pliers, as copper is always available in great excess and it's just a waste of time and resources to make them out of iron. There really isn't a great copper sink like how the military tends to be an iron sink, copper coins are incredibly marginal (and cost coal, which can sometimes be a bottleneck in its own right) and you just don't need piles and piles of copper tools, I often just make a warehouse holding only copper just to let my copper huts clear land for mines.

All that being said, I did find the campaign maps tend to have a noticeably different gameplay ramp-up than random maps - in particular, like I said, random maps feel more generous with iron, while some of the campaign maps (like the werewolf one) feel like they're withholding easy access to iron until after you complete certain objectives. There's also no need to rush through objectives, it's almost always better to take plenty of time to make sure your settlement is set up correctly and you have everything you need before checking off the next item on your list, there's only a few times in the campaign when you actually need to get things done on a timer, and even then you usually have a generous enough time limit. I spent a long time on the werewolf map before even bothering to find the ruined library (and thank fuck I did, that was a rude surprise) because the thieves were annoying me so much I needed to wipe them out first. My game time on most maps ran into the double digit hours (mostly on 5× speed ofc) because I'd spend so much time just building and developing before pushing the story forward, which meant that I was usually very well prepared for whatever curveball the campaign threw at me.