Obviously thoughtless actions. The Left engages in thoughtless actions and the Right in inaction.

Throughout history the world has been ran by those who take action. It may not have been the best actions, but actions nonetheless. These days everyone has an opinion, everyone is an intellectual, everyone is a genius. So, if there are so many geniuses today, how come we have an efficient systems in place? It's because thinking is very cheap and literally anybody can do it
It takes a special something to take action. Unfortunately, it's always the ones who don't give it too much thought that are taking the actions. I still say that thoughtless action is worse because it has real, measurable, tangible effects as opposed to actionless thought, in which the worst that can happen is you create a shitshow in the comments section.

“The ideal subject of totalitarian rule is not the convinced Nazi or the convinced Communist, but people for whom the distinction between fact and fiction (i.e., the reality of experience), and the distinction between true and false (i.e., the standards of thought) no longer exist (Arendt, , The Origins of Totalitarianism, [Peng. Ed.],622).

I vote other. It's been said already, but it depends on the situation. Sometimes acting is better and sometimes thinking is better.

Thoughtless actions have no limit to the damage they can do. Action less thoughts are simply lost potential.

That's a good question. But it would have to be put in a specific context. Sometimes the worse thing you can do is to do nothing. But sometimes you can't act without cautious thinking otherwise you worsen things.

Thoughtless actions. Action-less thoughts are likely to only impact you, whereas thoughtless actions impact those around you.

I’d say thoughtless actions, without question.

If you are at least thinking then you have some level of awareness, awareness of something always being the first step to doing anything worthwhile.

Then it is just up to us to expand on that awareness. I know for me, anytime I’m thinking about something but not acting on it, it seems to be a direct result of my personal fear of the unknown and, and more specifically, fear of failure as I venture out into the unknown. One thing I’m absolutely certain of, taking that first step and then “the next step” is how to get going. Simply acting as intelligently as I am able to right now, is the best I can do and even if I fail miserably, it is inherently better than not acting at all, as long as I keep taking the next step. We are learning beings, and I can’t learn without exposure and failure is the path to learning.

I am guilty of actionless thoughts and from experience they are worse. You can at least learn from wrong action.

What is worse - malfeasance or misfeasance? Answer - either or both. All depends on the circumstances and outcome.