Turtles need fuel to move but for no other action. I propose, that (if player/server opt-in via config) any action should use fuel.

This would make sense in terms of game design:
ComputerCraft is a very powerful tool, especially when using turtles. If CC is integrated into a Minecraft game with more focus on balancing and actual gameplay interaction it is very hard to put limits or add difficulty to CC.

Also fuel consumption can be turned off in the config, hence reducing game difficulty. There should be an option to do the opposite.

I have not looked at the code so I can't judge the implications of this. Still, I would be interested in arguments against this proposal and pointers to illustrative code. :)

Just nitpicking, but CC:T is powerful tool only in vanilla-like style modpacks.

I believe that this ignores the very OP item transfer abilities of CC:T that can allow someone to have autocrafting with stone and redstone (and some programming), unless you’re speaking exclusively about turtles.

You will get only vanilla-compatible autocrafting and, well, not a very nice one. Iron and diamonds are not so expensive in non-vanilla modpacks and refined storage or AE2 ofter provides more value much faster, especially if you consider that CC item transfer are wired only and networks are 64 blocks limited, if I am not mistaken. And you will spend a lot of time to configure, setup and probably partully rewrite this autocraft system. It is a lot fun, of course, but I doubt it is overpowered in any sense.

CC's item transfer system is definitely something which needs balancing, but probably off-topic for this issue. I don't think auto-crafting is especially OP, given that a CC turtle roughly costs the same as a vanilla auto-crafter.

Just nitpicking, but CC:T is powerful tool only in vanilla-like style modpacks.

I believe that this ignores the very OP item transfer abilities of CC:T that can allow someone to have autocrafting with stone and redstone (and some programming), unless you’re speaking exclusively about turtles.

imo the purpose of CC:T is introduce the fun of programming. if you don't program by yourself but just directly take someone else's, then you won't enjoy the time to make an "OP" achievement.

I personally do not against to add fuel usage to all actions, this may involve more challenge on base design. But I hope (if the idea is accepted) the default fuel usage/ratio can be balanced between actions (e.g. dig block (maybe) should consume less fuel than moving).

It is mainly an additional layer of challenge. Fuel in itself can be automated anyway and to require a more elaborate refuel-system early on would certainly add fun for me.

Auto-crafting aside, there are also havesting-turtles or wood-chopping turtles that, without moving, are oftentimes an exploit mechanism in my play style. Of course, this is opinionated - hence the feature request. :)

It's worth mentioning that currently, multiple cooperating turtles can move without fuel, as depicted in this image:

I think fuel requirements for turning make the most sense thematically, as turtle turning falls under turtle movement, and the other turtle movement actions require fuel. But that wouldn't stop multiple turtles from moving up or down by placing and digging each other.

Having thought about this a bit, and am afraid I'm not going to implement this.

I'm really not a big fan of config options which change the behaviour of computers or things they interact with (e.g. #1223). It's very easy to write programs which depend on a specific config value being set, and then won't work when shared with anyone else, which stinks!

As an example here, any turtle program which does fuel accounting (including the built-in excavate program) now needs to be aware of this config option, and have different logic for both cases.