Yes, minefield decay is a good idea - as I mentioned a while back, a minefield that decays at a rate proportional to its size means that the more mines you have, the more you need to maintain the field, and minefields will take a very long time to die away completely, so you won't have to worry about your minefields TOO much... see Stars! for a cool minefield system
One more thing I'd like to see in SE5 is taskforces... You can assign a fleet battle orders in SE4 like "attack planet" or "don't get hurt", but a real fleet is composed of multiple types of ships, which should each be doing their own job with orders specially crafted for their task. So what I want to be able to do is divide up a fleet into any number of taskforces, and assign battle orders on a taskforce basis - sort of like in Dominions 2, where you have multiple squads, each with their own battle orders, under one commander. I know you might say "well use multiple fleets" but then you have to multi-select them any time you want to give them strategic orders like "go to sector (5,5)" and that gets to be a pain (and I'm not even sure if the fleets stay together when one is faster than another)... it would be like if in Dom2 you had to multi-select each individual squad of soldiers that a commander commands to make sure they all move to the same place at the same time...
But I'd still like to be able to create fleets without taskforces (or vice versa, whichever seems more appropriate, it's just a matter of semantics
) and move ships around without assigning them to a fleet (or have that done automatically) - I *hated* having to create a new fleet with all the rules involved every time I wanted to deploy any ships in MOO3, even for the most trivial task!
