Does this work in reverse, with a bad feeling about all other options?

I don't know. If you're feeling stuck, and not particularly motivated to do anything, I generally think that it's good to try to find and feed positive motivations to do something. Avoidance motivations (for rejecting bad options) could just keep you stuck. And we want to keep things simple - one of the keys to all of these procedures is that you just need one option to stand out (positively) for whatever reason - you don't need to go through every option to rule all but one of them out. But if there are only 2 options and you do get a clear feeling against one of them, then maybe it is okay to base your decision on that - it's equally simple (with only two options) and it does get you through this decision. So I wouldn't aim to find a bad feeling, but if that was the first feeling that came up then you could go with it.

Ask someone else

I do that as much as possible, but it fails more often that not. Polite bastards.

You could try alternative ways of getting other people involved. e.g., Have them list the pros and cons of each option, and you listen and see if one thing jumps out at you. Or you could describe the options to them, with instructions for them to try to guess which one you'd. Or maybe just talking about the decision can help you clarify which option you prefer.

Though variety-seeking contradicts the others, and conflicting rules are Bad.

True. You may want to forget about that one if it could interfere with the others. There are ways to integrate it with the others, if you determine ahead of time when it applies. For instance, there may be certain domains where you want variety/balance. Or you may sometimes feel like you're in a rut and want to mix things up, and then you can decide that starting now I'm going to make variety-seeking decisions (until I no longer feel this way). The important thing is that when you're faced with a particular decision, you don't need to decide whether or not to seek variety because you have already determined that.

But variety-seeking is more of an advanced technique which you may want to skip for now. It's probably best to pick one or two of the heuristics which seem like they could work for you and try them out. Over time you can expand your repertoire.

Might be helpful to set up meta-rules. In any given situation, a hierarchy of which rules apply, or which to fall back on if the main ones are inconclusive. For example, variety-seeking could be one of the low-ranked options, seldom used but still significant for it's tendency to shake up the results of other rules.