I cannot tell you how thrilled I was to wake up and see so many responses! Let me try and address everything. I will be putting up new versions as changes/improvements are implemented.
(Responding to the comments in order)
1. Type of speech can definitely be added, although that would again make it harder to put in a longer definition. Will play around with single character markers, then a key at the bottom.
For kanji puzzles, the format will be completely different (Because kanji terms are often just 2 kanji, a traditional-style crossword puzzle will not suffice. I picked up some kanji puzzle magazines to get some ideas, but many of them take more of a shiritori form, where instead of across and down clues, each clue latches onto the one before it. There *are* traditional kanji crosswords, but they are SO tightly packed that I am not sure the site is (or could be, given time restraints) smart enough to make one without taking a LOT of processing time.
2. How often - please see the bottom of the post
3. I will have the clues follow one another instead of split into two distinct rows. Thanks!
4. I can do away with the blackboxes fairly easily, although if we are to save ink, it would be best to do some kind of hashing/cross marks, or do away with them altogether.
5. It is ideally functional as well, so let me know which clues are missing (or just a couple). Keep in mind that the numbers are not supposed to be in order, so there will be gaps in each of the across/down lists.
6. The clues could be moved to a second page, but that doubles the number of pages needed to print it (I don't think most people would opt to print both on either side of the same paper - it would be a bit troublesome turning it over repeatedly), so I am a bit hesitant to do that. I haven't yet actually printed it out, so it may be that certain parts are much too large/small when actually in front of you on paper.
7. FREQUENCY
The puzzles can be generated automatically, but it a)takes a bit of processing power, and b)there are *often* groups of words that do not make good puzzles (more kana than ABCs, typically much shorter words, etc). So, for now, I do not see a way to allow users to say 'make a puzzle for this group of terms' and expect a consistently decent puzzle.
Furthermore, I would like to expand the renshuu pro offers, so I want to split it between free and paid users. Here are my thoughts:
Free users:
Have maybe one puzzle (maybe one kana, one kanji) for each JLPT level available for free. These will be rotated out biweekly or monthly. This will also make it easy to distribute the puzzles through things like facebook and help attract users to the site.
Like pro users, free users will be able to adjust the size and/or various options with the puzzles, but the wordsets will be predetermined.
Pro users:
I would like to offer pro users a much, much, much larger set of puzzles to choose from, which will be rotated every few months. Maybe 30 or 40 (or even more) for each JLPT level (of however I decide to break up the groups). Even after they are rotated, any previous puzzles will most likely still be available in the archives.
I have not yet come up with a good way to display that many other than...a rather boring list of 'puzzle 1,puzzle 2, etc'. Hoping to make some kind of simple management system where you can easily mark which ones you have downloaded, completed, etc; this will make it easier to get new ones later without having to worry about repeats.
Obviously, the ideal solution is to have dynamic puzzles similar to the kanji worksheets, where you just feed it a collection of materials, but that simply isn't possible with the limitations of a puzzle. If the worksheets are all preprocessed, I can devote a lot more processing time to each puzzle so there can be hopefully be more terms with tighter, smaller puzzles.