I think the salvage gantry might be a bridge too far considering this is the 'base' level cruiser in the game. It can already reduce survey costs.
But I very much agree that an unlocked fighter bay like versions past, would make the ship somewhat more attractive for general use.
One of the reasons the Venture exists in the fashion it does and is assigned to the default base_bp, is to give in-game factions without access to a heavy industry the ability to field at least something that does a passable job of being a fleet anchor.
With the limited ability act as a carrier, the Venture would be a little more effective in this role for the tradeoff that the OP cost of the fighters still has to come out of the ship's loadout thus reducing it's already limited combat potential. This incentivises the use of 'cheap' fighters, but still leaves the option to specialise in that direction if desired.
If this is still too unbalanced for your taste, you could also consider removing the fighter bay and giving the Venture a built-in converted hangar. This would effectively restrict it's use of bombers, and even further incentivise the use of the cheaper fighters.
Gantry > Survey equipment. Just my opinion of relative value as Survey equipment only means less heavy machine needed, which is not something I miss or even notice if I'm missing. I get it from the angle of OP cost, but at the same time I feel like all the support type mods are overpriced. So if I had to pick, Gantry would be better and suit how it gets used in game. Both Pirates/Scavengers would have a RP and game mechanics reason to use one, more loot. Currently both those groups use no Salvaging Ships, which you'd think would be logical for them to do.
Converted hanger bays would be fine, removing the pointless mining drones. Now that I'm thinking about it I'm not sure why there is no upgrade to mining drones, I mean there should be a Military/Pirate/LP variant that is better (more costly too) suited for fighting.
Ventures description for quick reference.
"Tough, dependable and not overly expensive, Venture-class cruisers are usually constructed by private corporations for escort duty or by small non-aligned worlds for system defense.
The Venture-class ships are perhaps the most widely used civilian cruisers in the Sector. The blueprints for the Venture are widely available and can often be secured without too much trouble.
When used by small corporations, the ship is usually the pride of the fleet and is used to underpin vital operations. Due to its ubiquity, the vessel also serves with quite a few pirate outfits, where it sometimes fills the role of command ship." –In-Game Description
It doesn't seem to be a specific mining ship, so the mining drones are there for no reason. I'd argue it's cost is rather expensive as in terms of literal in game credits, for another 10-30k you could buy a far better cruiser or buy 2 Collossus Mk III (generally better in every way).
It should be widely used for a reason beyond it being common. If you wanted missiles, Kite spam with missile racks, that's cheap and deadly.
The Anvil and Anchor stuff is personal strats and not a reason to buy or/build or even want a Venture. It being a common BP should be matched by a logistical reasoning in game for it to see such wide used. Currently the reasoning seems extremely meta, a big fodder ship.
edit:
I agree with you Eji1700, mining drones could have utility attached to their existence as they are non combat in RP but do nothing non combat in mechanics.