Regarding your question about cyano, just about all the internal " frame " joints are glued using cyano, and when "fixed" are solid, if you have to undo the joint you have to physically tear apart the plastic the joint is VERY strong.
Make sure that it is right first time or you will have probs trying to fix it if its not in the correct position.
Build the frame up DRY first to ensure all is correct AND NOT TWISTED. I have seen some where the internal frame has not been given the care attention that is required when building and it looks awful and sealing problems follow later.
When correct you can always go over with Stabilit Express to reinforce the joints if you wish. I would reccomend STABILIT EXPRESS for the rest of the build as ROBBE do , not a cheap glue but very durable and it will stick all the brass parts to the plastic too.
It does pong a bit so do it when "she" is out for the day unless you have a centrally heated workshop / shed that is
If you are going for the Engel tank dive system you need to mod the internal frame / tray from the start to allow for the tank and reinforce it at certain points, just ask and I will give you some info and pics ( if you want that is ).
Also the screw joint needs SILVER soldering too, there is a lot of stress put on this one piece of the kit and I have seen / heard of this snapping when screwed in on some boats when soft soldered as it tells you too in the instructions and its a hell of a job to get it out again when half of it is stuck in the boat !!!!! >:(
Hope this is of use. regards sub