I do individual trips that include surveys of 30+ planets; having surveying equipment on multiple cruisers easily saves me multiple thousands of supplies. I guess your trips are just one system at a time rather than clearing out multiple constellations?
Generally I just survey planets with ruins or planets I think might be worth settling. I guess if I wanted to go all completionist I'd require one. I can see which planets have ruins so why am I scanning some pointless Barren or w/e world?
That sounds like unproductive busy work.
Check the sell price for surveying data. The only one not really worth the time and effort are class 1 worlds. If you have a fully decked out surveying fleet, where even gas giants only take 5 supply, you can make a LOT of money surveying. Plenty of class 4 gas giants, volcanic worlds, toxic worlds, barren worlds even. Ultrarich veins can happen anywhere.
My exploration fleet tends to be an Apogee if I can find one, four Ventures, assorted support ships like a few Drams and cargo haulers, all with Surveying equipment if I can find it. Given how bountiful some systems can be, with derelict ships and probes, and other such things, it's quite easy to hurl myself off into the far corners of space and only be limited by how much stuff I can carry, not the size of my fuel tank. Give them all militarized subsystems, have the +1 burn skill, and suddenly you can outrun anything you don't want to fight, and chase down anything you do want to fight.
The Venture will never be a dedicated combat craft, and that's alright. It was not designed as one. It's a civilian exploration craft, and should be used as such. Militarized subsystems allow it to explore better, not fight better. Less sensor profile, more burn means I can hope planets faster, and cram more crew into less ships when I want to finally settle somewhere.
I feel like this is the key. A ship really only needs one purpose to be the reason it exist. While being common may not be good enough for some people to justify getting it themselves, it could be good enough for others to pick up the ship instead. After all, that's why you will more likely then not see this ship in fleets and it's the reason the ship is phased out later for better options when available. The
only reason I would feel like the ship needs to be rebalanced is if there was a ship that was equally available that was superior to it in all aspects (price, fighting aiblity, usefulness). As long as there's a plus side to a ship verses another (even it being just being more common), then it's fine in my books.