
While I understand the worry, I don't think it's a problem. A journal can give insight on a character's psychology and also work as a record of sorts for their adventures. If that OOC information is used ICly, it should be dealt like plain old metagaming.
I also don't know anyone whose character suffered for keeping a personal journal around. Characters evolve as long as the player plays them, so no matter how much detail your journal (or wiki page) reveals, there's no saying how or what the character will do until the interaction actually happens.
On the matter of too much information on the wiki pages, which is related, I'd say you shouldn't worry either. Though I have found myself more eager to read the shorter pages while avoiding the larger ones (or just read a small part of them), unless I have some kind of interest with the character. The same happens with journals, really. The only people who will surely bother reading your journal are those players you roleplay with already.
Journals and wiki pages are a personal excersise of character building. Specifically speaking, journals force you to meditate on how they personally take the events around them on how they affect them. In a way, it's a form of character development. It is a handy reference guide about your character's actions, which is in itself useful for future reference.
In short: if you enjoy writting it, do it. There are no real downsides to it.
I also don't know anyone whose character suffered for keeping a personal journal around. Characters evolve as long as the player plays them, so no matter how much detail your journal (or wiki page) reveals, there's no saying how or what the character will do until the interaction actually happens.
On the matter of too much information on the wiki pages, which is related, I'd say you shouldn't worry either. Though I have found myself more eager to read the shorter pages while avoiding the larger ones (or just read a small part of them), unless I have some kind of interest with the character. The same happens with journals, really. The only people who will surely bother reading your journal are those players you roleplay with already.
Journals and wiki pages are a personal excersise of character building. Specifically speaking, journals force you to meditate on how they personally take the events around them on how they affect them. In a way, it's a form of character development. It is a handy reference guide about your character's actions, which is in itself useful for future reference.
In short: if you enjoy writting it, do it. There are no real downsides to it.