Nav Buoys and Sensor Jammers should be more worthwhile
I would suggest the alternative of removing them. But since the topic is about improving them...
Taking a step back re: objectives, they exist entirely to give you, and the AI, a reason to split up your forces. I'm not saying the current solution is ideal, but I think any ideas about how to adjust them have to keep that goal in mind. Heck, I'm open to removing objectives completely, provided there's some other way to achieve that design goal. To put another way, the feature isn't really "objectives" but "reason to split forces apart"; objectives are an implementation detail.
As long as the player can focus-fire on a target, that will generally preferable than to divide firepower, often to the point of ordering Eliminate (or Fighter Strike) to destroy priority targets. The one time I remember letting my fleet split-up is when I run frigate mobs of about 40, and only twelve of so can attack a target at once (though homing missiles passing through ships help for a time).
I guess one reason why weapon ranges in general are so short is the make it harder for everyone to focus-fire on one target if the ships are forced to spread out. Then again, that seems to make everyone, especially AI, gather around for the infamous death ball fleet.
Other ways to achieve goal:
1. Force civilian craft to deploy alongside combat craft; player has to simultaneously defend those fleet assets whilst attacking enemy.
2. Put capturable objects into the game that activate and hold an area effectively (this was done in Vacuum with the first Stations and it was fun and interesting). Say it's "Domain tech" that your fleet "hacks", and voila, stuff that's a bonus defensively is a thing.
3. Put capturable objects that reward the player in non-combat ways, such as Credit drops, Blueprints, or even something that affects capture / repair, that incentivize the player to hold / keep the locations but don't have an immediate effect on combat balance.
1 may be cruel. Normally, I would say that I would just bring hybrids that can fight, but that is not really possible since most fleets (that are not bumming around core space for faction warfare) need a tanker, plus hybrids are not great at fighting past a certain point.
However, if ships can retreat the way they came, then player would retreat them ASAP. That is what I did during 0.5.x when small battles auto-deployed all. It would be a CP tax to keep strategic assets safe.
Plus, another defense for that is to bring so many ships that it is impossible to deploy all.
3 sounds like something. The rewards of keeping objectives could occur after battle.
* Deployment costs are reduced. Sort of like free standing down and recovering CR.
* Salvage multiplier. (I have save-scummed fights before for rare stuff.)
Like Xenoargh, I use points mainly to cheese AI.
The +25% bonus from (one) Comm Relay is small enough that I ignore it, maybe it would be worth it at +50%. Currently, I never bother with Comm Relays unless I can cheese the AI with it.
His idea to slow CR decay is a nice one too, although that may be of limited usefulness once the loot bug fix is in. In which case, better to retreat all then fight round two. Currently, I do not retreat from battles because I lose so much (potentially rare) loot (but not the XP) if I do.