All right, quick guide then.
Useful abilities for not dying early: Attack Speed, Armor On-Attack, Aegis. Get some Max HP and HP Gain On-Hit or Lifesteal
Useful abilities for not dying later: Stun (don't need that many), Damage Resist, Status Recovery Bonus, Frost (esp. w/ Enchanted Attack)
Once you get Evil: Demon Shop
Useful abilities for killing the spider early: Reduction Shredding, anything that increases physical DPS.
Useful abilities for killing the spider mid-game: Bleed, Poison (w/ Enchanted Attack).
Once you get Evil: Corrosive Poison, Ghost Blade (very late game only).
Utility: Skill Cost Reduction, anything XP/gold-related
The real reason spider max health scaling doesn't matter is that by stage 100, almost all your damage will come from %health dots anyways, so you kill it at pretty much the same speed regardless of health.
To be more specific, it seems like there's a bug related to skills between your ghost and the spider: when you fight your ghost, it has stats and skills corresponding to your build from the last game, but then on the following round the spider appears to keep your skills while reverting to its stats, thus giving it your very high damage output combined with its enormous health and armor pool.
The cleric and warrior are very relevant for quests, and some guardians, which can help get more upgrades for the archer and for your base (which can help get more upgrades for the archer).
Hey, I have an idea. Let's make an enemy with 9 million health. And let's make him immune to pierce. And then, I don't know, let's make him dispel rage so you're just going in with your base attack. And THEN let's make it so that if the battle takes too long you all arbitrarily start taking damage and die. That sounds like a fair and fun fight.
I'm not sure how the thrust calculation works but as it stands, low power stages are completely worthless. Even if you use balloons to drop your weight to nearly nothing, a prop-type will never exceed ~20 speed or so and will burn all its 2000+ fuel supply lifting you maybe 20k, assuming you don't hit anything. They're neither competitive with rocket-type components nor effective in any absolute sense.
Every couple of minutes I lose control of the vehicle, it won't let me steer and just acts like I put a cinderblock on the gas. It kind of makes it hard to, you know, play.
The game is great except for whatever is causing me to be unable to control my freakin' ships. Ships regularly advance even when they were specifically ordered not to, or turn around and flee when they were ordered to attack.
Why is it that the enemy has ridiculously superior knockback all throughout the early part of the game? Even if I do nothing but train agility, even if my melee outnumber theirs, I can't protect my side of the field because I just get punted all over the place.
Upgrades of production structures are valuable up until about rank 7, but you really have to be in this for the long haul to justify upgrading any further. Upgrading a logging camp from 7 to 8 costs 28050/18000 plus 6000 in lost production, and a mine costs 28000/14000 plus 5040 in lost production, for an increase of 30 resources an hour (and an increase in cap, but unless you can't check every day this probably won't come into play). If you upgrade one of each it will take 86 days to recoup the lumber and 51 or so to recoup the metal.
I'm really not terribly enthusiastic about the prospect of sitting here and grinding the first boss another 50 times to try to get the rubies I need to make the most basic gear.
Two things: if the delete all function is used, achievements and the "like" bonus should be reset. Also, most of your first tier skills are weapon-specific. In a game with random loot and low income, it's bad form to force players to commit to using equipment they have a good chance of being unable to obtain.
To be honest, I found that the greatest complication in getting all perfects is that the no-longer-needed cash shooting towards me across the ground triggers my projectile avoidance reflexes.
Okay, just one major flaw as I see it: on the level 3 world map, it's not uncommon for one guy to spawn in the western hemisphere alone. That guy is virtually guaranteed to win if he doesn't play like a total idiot or get horribly unlucky in combats because of the the fact that North America provides a large income and it's very easy to control the choke points. Even if someone were to start in South America (with a guy in North America), they are virtually no threat because South America only has 4 income for the entire 8 territory area; that guy is better off relocating to Africa or something. Meanwhile, the other three players will be killing each other to try to make a decent income in Eurasia, so eventually the guy who holds the Americas will be snowballing over them with 90 army groups.
Level 3 and the Crazy challenge are the two levels with random start points, and there is luck involved. It's possible to win from any configuration but some are harder than others. You can start the level over a few times to get a start you like.
High level warrior with the right gear and buffs: Immune to poison. Immune to stun. 99% (maxed) damage reduction. ~20% of max HP per round in health regen. Will solo Pandora's Boxes after the rest of your team is ignominiously killed in round 3 (stupid minotaurs).
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Low speed + high fuel items pair with low top-speed bodies. The rest works well with high top-speed bodies.