I would like to have a radio button in the settings page to switch on/off studying of words.

Does that make sense?

So you'd only do single characters while the multiple-character words are switched off?

It would be difficult to do that--the data are all organized around pulling different parts (writing, reading, etc.), styles (simplified, traditional, both), and languages (Chinese, Japanese), from one or all lists, but we're not set up to efficiently discriminate between multiple-character words and single characters. We'd have to add a lot of complexity to pull it off.

I'm curious: what's the reasoning behind wanting to switch the words off? Would you leave them off, or turn them off and on frequently? Have I misunderstood the idea?

I was thinking about this already some time (I prepared a wishlist, in order to collect all suggestions and submit it one time, however, I didn't do so far).
I would even go one step further: I would like to mark entries as: character, word, idiom, chengyu as well as measure word,conjunction word, radical and might be others.
That would give me the possibility, to review for example:
- all characters, as it is much harder to remember a character than a 2-char word (it carries less information than 2 characters do), characters can have so many different meanings, so that I would like to give them some extra effort (I know, that a lot of people only want to learn words, I don't want to start here a discussion about this, but that is, what I want)
- only study measure words, I'm annoyed about myself, that, when speaking, I mostly use 个, a regular review on 100 or so measure words could definitely improve this. Normally, I get characters, which at the same time are also measure words, but to get e.g. 100 in a row on one day and do this for 1 week, would definitely make a big difference,
- I think the same is with conjunction words, their meaning and usage is harder to remember than average characters,
- same for idioms and chenyu.
So if it would be possible, to mark an entry into such categories (one or more), this would be quite helpful. For the measure words, I already started this with Anki, but I don't like the idea, to use 2 different programs, instead I'm really a fan of Skritter.

Roland nailed it.

Frank

You can already do this. Put the specific characters/words that you want to study in a custom list and study only that list.

James

We're going to be working on a feature to make it easier to copy words from one list to another, which could help for personally categorizing measure words, idioms, etc., into lists, but probably wouldn't help very much for single characters since there'd be so many of them.

Making the lists more manageable would be helpful. I'm self-learning, so I don't have a curriculum to follow, and hence have been using the prepared lists. Subsequently there are words that give my problems that I may give a low priority for immediate necessity. When I select 'forgot' or 'so-so' option, I just seem to be punished over and over. I've been adding those to my star list and marking them as favorable so they stop re-occurring so frequently.

Since my ultimate goal is to become fluent, I don't want to drop them from the list completely, but would rather pull them into side lists where I can focus on them exclusively for 30 minutes, once a week to help curb frustration.

But all in all, my biggest problem has been writers cramp in my hand since getting my bamboo. :-)