Mobile Anti-Nuke Unit

I don't have anything against supcom 2 since I haven't played it, but most of people will hate on you if you mention that game. Probably because it took a step in to popsite direction of what PA is doing,

wouldn't a naval cruiser with anti nuke fill both roles?

I very much support such a unit. Make it slow and have lots of health.

Since nukes are so common in PA, they negate large ground forces in late game. Nukes also make teleporter invasions difficult.

Teliporter invasions are frustratingly difficult in general. The enemy can keep shooting down your orbital units as soon as they enter the planet's sphere without you even seeing what's going on.

Should make them, but only on Naval and Tank IMO. Then have them carry only one, and have to gather them from standard antinuke silos (ie not be able to make them themselves)

I'm not sure what I think about an anti-nuke tank. That might be too much symmetry. Air land and watter are supposed to feel different. Water should be different from land by having units that behave similarly to buildings. A battleship is a floating artillery, a nuke sub is a floating nuke launcher, and an ABM cruiser is a floating anti nuke.

I also disagree with the idea of mobile anti-nukes not being able to make their own missiles. They would be the ONLY unit that is incapable of re-arming itself. Even in TA and SupCom the only units that had to re-arm were air units, with strategic and tactical missiles be made by the units that fired them. Introducing a mechanic for anti-nukes to rearm back at the base (how would an anti-nuke ship even get to a land based anti-nuke silo? Or even an anti-nuke tank for that matter, would the anti-nuke silo have to get some kind of ramp or crane to load units with) would be adding complexity without adding depth and makes no sense when every other unit is capable of magically re-arming itself.

Satellite based anti-nuke. Could be a laser with a high energy drain to charge. Give it a minimum charge time of 20 secs (or whatever length of time is reasonable) and if you don't have the power, the charge time will be longer. You could operate several in the same area to defend against swarms of nukes, but the high energy charge cost would require you to have a vast power surplus (storage and/or production), otherwise all of them would operate at a reduced firing speed.

They would need some sort of system to only have a single anti-nuke weapon fired at each incoming nuke, so you're not wasting laser power or anti-nuke interceptor missiles. Earth 2150 had SDI anti-nuke lasers, but if you fired 2 nukes at the same place at the same time, all the lasers would fire and overkill the first missile, and then the second would drop in unmolested.