Help needed, please......

Apologies to all you seasoned forum creators/ administrators/ users, but I am new to all this..... 
We have created a private forum for our friends' wedding so that guests can exchange travel info; gossip about the day, the people; Hen & Stag Night details can be discussed etc etc etc. , but I am struggling with some of the basic set- up stuff.
1. We set up a few categories on the Forum page, but the first category (although I notice it is called XYZ Forum "topics") has taken a bolder & larger text than the rest even though they should all have the same "status". Furthermore, it (the first category) seems also to have become a bit of a hoover,  as some, but definitely not all, topics that are started in other categories appear as well in the first category. I cannot seem to change the font size so that they areall equal from the admin panel, nor supress the intermittent hoovering. Any ideas?
2. Some users start new topics when a topic covering their subject already exists. I cannot see how to move topics into common topics. I can move whole categories, & I can move topics into different categories, but I can't (effectively) merge common topics. Any ideas, please? Do I have to change the subsequent topic title? (If I can even do that.....)
3. If I wanted to create an excel spreadsheet onto which users travel plans information was entered, can it be done? If so, how? What I don't want is users inadvertently deleting/ messing up stuff...... Again, any ideas?

Apologies again for the "blonde" questions. Lefora is fab.- it's me that is causing "user error".
Thank you.