Henchmen do not just appear on the world stage like in EG1.

If you open your objectives screen and along the top click the side story tab you'll be presented with a list of side stories. If one is for henchmen recruitment it will tell you such. Choose the henchman side story you want and then they will appear on the world stage.

Typically as a large spinning icon with arrows pointing to it and a head silhouette on it.

The text for this needs rewording as you don't need to dig down to the lowest level for the super weapon at all.

Every map has a large black pit on it somewhere, all you need to do is build a connecting corridor to it to complete this objective.

Stairs are a bit finicky where they are placed but you DO NOT need T3 research and beyond in order to place them.

If it tells you that you need hardened mining e.t.c. then the issue is not your research but the placement of your stairs.

You need to rethink your placement and put it in a place where the lightest and next darkest colour dirt is on your map on ALL floors you wish to reach in your placement location.

As an example, on the third island map I have managed to place one set of stairs that connects all possible floors.

This I partially agree on.

However when not in building mode if you're struggling with rotation I find Q and E to work well and save some of the annoyance.

In your casino on a lot of the items your valets e.t.c. can use you have the option to turn on scam tourists. However, in doing this you remove the ability for the thing to be used by agents.

Scaming tourists will earn you money, there is no consequence for this.

I advise you to have a mixture of scam and not scam setups so that you make some extra cash from your casino and get agents to lower their resolve and skills.

With lower skills agents will not disable your traps and will be hit by them.

I've found this typically happens if their resolve is still too high.

When an enemy is taken to a cell their resolve will tick down till it reaches zero. I've found interrogating them at this point nearly always results in a 100% success rate.

As for the escaping, it happens from time to time but only from the more advanced agents. Have guard posts outside your prison doors for this purpose.

Anyone that has had lots of body bags littering their lair after a fight with a super agent is more than likely aware of the desertion spiral that happens due to low morale because of all the bodies which leads to bodies taking longer to clear which leads to more desertions.

To solve this build a decent amount of incinerators. Perhaps even have a power room of only incinerators.

To explain, only one minion can use an incinerator at a time. This includes travel time.

The more incinerators you have the more minions will actively clear bodies at the same time. I've had no desertion spirals since I started using more incinerators.

Any other major issues I see in the discussion forums or that gets requested in the comments I'll do my best to answer. But please be aware I actually have to encounter the issue myself or work out how to combat it through my own playing first.

Note that all of the above is from my own testing and guesswork but largely seems to solve a lot of the issues in my eyes.