[Puke]

mechanically, planetary shields work just like armor. Make a facility with the shield ability, and call it armor. It will work the same, i.e. take damage first. be sure to give it the phased shield ability, so phased weapons dont skip it.

The biggest finished mods are Pirates & Nomads, Devnullmod, Proportions, and the two Startrek Mods. There are many other derivative mods and in-progress mods. There are tons of smaller mods, many of which are better than the big ones.

There are a couple mods that are even "bigger" than the ones that I listed, but I dont think they are as well polished.

Some mods are made for single player with AI, some are multi player only (no working or good AI).

It all depends on what you want.