They were too expensive in 5th edition, when they were more armored and could claim objectives. Now, they are just too much. The only reason I would take them is to get more vehicles on field in order to break my opponents target prioritization.
Fusion blasters work. Inefficient, but they do work.
My general rule is to make as many units as possible. So if I have 3 suits, they are 3 monat units. If I have 6 suits, they are 3 pairs, so on and so forth. In my 2000 point lists, I typically grab an extra commander and some more fire warriors in order to unlock more elite slots so I can further split up my suits. Now that we don't have target locks on our suits, getting as many independent units as possible is important.
I disagree. My elites slot suits are all twin-linked weapon + targeting array, team leader has a HWBSF. My bodyguards and commanders are all MP,
PR,TA,HWMT. Commanders get a HWBSF and drones if I can afford them. My elites teams are typically Deathrain, Bladestorm, Sunforge in a 2:1:1 ratio, depending on points. Sometimes, I don't take Bladestorms, as we have a great anti-horde option in hammer heads, and if I bring broadsides, I typically drop the Sunforges. But my bodyguards are always Fireknife, and I haven't run a 2K list without at least a couple in a great while. Of course, I always take as many commanders as I can, and they are also Fireknife configurations.
I disagree entirely. If the codex could let me field an all suit army, I totally would. It would be awesome and glorious. Sometimes, I bring 2 minimum fire warriors squads and a hammer head and then just spam suits in a 1500 point list. Depending on composition, I can usually get 15 or so suits. Now, this army has a significant disadvantage in objective based games, and I wouldn't bring it to a tournament, but it is ridiculously fun to play. Especially if you deep strike everything.
That being said, you have mostly great advice there. I would just add that the suits have a move distance of 9" - 24" if you run and 8" - 18" if you shoot. The average distance if you run is 16". The average distance if you shoot is 13". Remember those numbers, and use them as a rough guide as you try to slide into better positions, not just bounce back and forth into cover. As of 6th edition, you can always measure distances, so use that and the law of averages to your advantage.