I touch type all the time and I am quite confident on my keyboardYeah you'll be fine with blank keycaps. ;)
More importantly, why do you want to use blank caps so badly? Because you see others do it? Is it actually appealing to you? I can use blank caps perfectly fine any day, but I just love the look of legends on caps. They add more to the looks and pleasing aesthetics to me personally. I know others truly prefer the blank look.
Here, I give you an image of a blank keyboard. Now without looking at a keyboard with legends label each key...Show Image(http://i.imgur.com/pXXUdyq.png)
did you get them all correct? Congratulations legends are only decorative for you from now on.
NO? Well, go blanks and learn the hard way. You can force yourself to remember where everything is eventually. :))
For me it was a spatial thing. With blanks, the rows of same looking keys pushed the placement around in my brain and I would wind up doing things 'kujw rgua' instead of typing 'like this.' I need an occasional glance to reassure myself everything's OK, so the trial by fire method's never worked right for me. :-[
I have a similar question. My keycool 84 has macros programmed to the F keys such as volume up and whatnot. So if I get a replacement cap without said printing on side of cap telling what that key does, will I get used to it quickly, forget about the macros, or get them wrong, as regular keys are simple to remember, but macros that are usually unique to one board aren't.
It's interesting since you talking about one hand typing and so on. This is exactly why I memorized everything (in 2 layouts, US and RU for me) so if I need to type one hand I can imagine the correct place for each character from the place it should have. I don't use blanks much anymore, I only have one board with them, but I do have a few other boards that have other language layouts on the legends but don't actually use those keymapping in the OS. On my primary use keyboards my numrow only have numbers, no shifted punctuation legends. So it still comes in handy knowing where things are supposed to be. It's a little slower without the proper legends since you have to think a little when one hand hunt and pecking but it is doable without getting yourself frustrated.
Also, I can put on a set of caps very quickly these days without really having to think about it much. Kind of like a military man reassembling their firearm. :))