For those a little confused by the topic title, take a gander at the scenario below:

Right now, we have three turret upgrades:
Base Turret
Improved Turret
Gatling Turret

And two mine upgrades:
Mine
Two Mines

And we know in the upcoming DLC that there are Pyro Mines coming up, which seem like another increase. And then we have the Molotovs currently, which chances are will become the Napalm versions mentioned in the DLC, which leave fire around the area, much like the Caltrop grenade belonging to the Operative.

But is there more that could be done with Ability Adjustments? Branching upgrades, perhaps? I think this would be a pretty good reason for people to start creating more characters of similar class builds, etc.

For instance

For example, After you have unlocked the Improved Turret, you could have two or even three options:
Gatling Turret - as seen in game, high ROF and decent damage output
Grenade Turret - slow ROF, maybe around the same as the Lobster, but fires grenades instead (obviously suited for high vantage points and suppression)
Shield Turret - Same offensive specs as the Improved Turret, but has a large shield behind it, ideal for taking cover - more suited for ther midst of battle

You could only pick ONE of these at a time, obviously. This would mean that people could mix it up between their offensive-based playstyle, a defensive one, or a disruptive one (Grenade Turret being placed in a otherwise inaccessible vantage point by a Light, to knock everyone down in range so they can be picked off seems a good idea, no?) If you had ability points to spare, then you could buy more than one, and change the type at a Command Post, same as weapons.

Other examples:
Mine
Two Mines
Then branches to -
Pyro Mine - column of fire, as described in the DLC
Disruption/EMP Mine - disables Turrets or the Bot you need to escort for a brief time, alternatively, messes up the opponent's vision (flashbang style) or even screwws up their minimap/entire HUD.

These could be applied to the Satchel Charges, perhaps.

Obviously, these type of upgrades would be applicable for every class, not just Engineer bonuses. In the upcoming DLC, the Medic can plant a regenerating beacon. This could be expnaded upon:
Regenerator
Improved Regenerator (wider AOE or increased regeneration)
Then branches out to either -
Bioweapon Dispenser - any enemies caught in the area take damage constantly while in the area
Charged Regenerator - Any mines, turrets, hacking devices, etc are slowed/disabled while within the circle

...you can see where I'm going. I'm not going to list every possible idea.

The point is, the abilities right now on the whole are very good, but I think specialising them more would really add to the customization options in the loadout. In one match, you could have your Heavy Engineer laying down fire with his Chinzor, cleaning up everyone who got bowled over by his Grenade Turret, or wreck the escorts of the Escort Bot with some well-placed Disruption Satchel Charges, blinding the entire patrol and ambushing them with your team.

Thoughts? Improvements?

Agreed on all counts but one:

Caltrops are an Operative ability.

Also, I think they should branch into Grenade turrets earlier, as an alternative to Medium Turrets, slow-firing, and much like the Lobster. Rank 5 upgrade to the Grenade turret could be a fast-firing AGL Turret. You could take both at each level, but you'd have to choose which to deploy (deploy one after the other, the first will be replaced)

Yeah, I dun goof'd there. Consider it fixed.

I like it, I do not think this game ought to have abilities of different ranks, simply because it makes the higher level player better than the lower by default. And also because SD specifically stated that the abilities will not necessarily be better at higher level, just more complex, and therefore they would like you to master the simpler skills before using stuff like the lazarus grenade - but clearly this is an example of them going against that. Good ideas mate, it would be great to see some more variety and perhaps have the community to contribute with their ideas. Perhaps you could compile of list.

I think that this is a great idea and they should have launched with it... they have lost many people who would have been very happy with the game if this was included from the start.

It is exactly what the game needs to set apart your character from all the others. I hope they look into this.

I totally agree with your idea.

personally like the idea very much especially with new lvls coming in it would help with the evolution of abilities with lvls. SO u could have alot of different abilities say when ur lvl 30 or have a few that have be upgraded to the higher ones such as ur mentioned shield turrets