Welcome to our Forum, Seera.
Let's see if I can address your questions.
1. My first chapter is going to feature the apprehension of a burglar using what shows up in the game: a fight scene covered with a dirt cloud. Would this be appropriate for this forum? I don't plan on putting a big sign in front of the house saying: please come rob me or anything so burglaries shouldn't happen too terribly often.
Showing the fight scene is fine. The game censors it enough to make it appropriate for this Forum.
2. I do play with a few mods mainly to fix things and keep my game running smoothly. Since I'm hosting my story on my blog and advertising to other forums names to those mods might come up. I know I can't name them here, but would it cropping up on my blog be a problem? I suppose I can just post it in here, but I'd rather just post links to the blog so I'm not redoing the images (changing url to bbc code and resizing them since they're bigger than 640x480, I believe).
As long as the mention of mods isn't blatant or prominent and doesn't have links, I think it will be ok. Also, just so you know, if you use our Gallery to upload your Sims 3 images, it will automatically re-size them to the correct size for the Forum.
3. The spouse for my Differences in the Family Tree challenge is Neone Clashe. Her LTW is to be a Master Romancer. Of her progress towards her LTW, how much can I include and not become inappropriate? I don't plan on getting super detailed, but I would also like to acknowledge that she's working on her LTW if I choose to go for it.
We can't really tell you not to write about something that is clearly part of the game. As long as it's written in good taste and not terribly detailed or "dirty", it should be ok. The only small concern is that it'll be infidelity in a big way. But still, that's what the game allows.
4. Also if I do end up reposting here since my chapters are probably going to exceed 25 with duplicate posts removed most likely, would it be fine to double post in those instances? My chapters are basically going to end where I think it is appropriate, not because I've reached picture #25. I have 66 possible pictures for Chapter 1.0 and I only played for 4 Sim days. I highly doubt my chapter will be 66 pictures long, but I'll probably still exceed 25. I'm still in the process of writing it though
If you mean to deliberately post one right after the other for the sole purpose of having 66 images, I'd have to say no. It becomes an issue of loading times and available bandwidth, so we have to stay firm on the limit of 25 pictures per post. From my own personal point of view, I've often seen stories that have a lot of pictures just for one action. For example, there will be 4 shots of romantic interactions. Or perhaps 4 shots of working in the garden. The extra shots really aren't necessary for the story and could easily be left out. Also, the idea isn't to stop your chapter when you reach 25 pictures, but rather to use no more than 25 pictures to illustrate the chapter. There's a fine line between the difference, but perhaps you understand my point.
I appreciate your concern for following the rules of our Forum, so thanks very much for posting.