1. no. I love different patterns or color on top. Think about it: If you wear jeans, how often do you wear a completely denim top? Mismatch!
2. Do you mean price? I go to thrift stores for most of my stuff because I like vintage. But there's no "too much" it just depends on your budget. If you can afford Dior Gucci and Chanel, you go on with yourself! There are no rules here.
3. No. I have three pairs of flats: a sandal, a pair of black flats, and a pair of leopard print (surprisingly versatile! I'm a big fan of leopard print with otherwise simple outfits, it dresses up everything)
4. See above. I also have one pair of brown leather boots I wear in winter when I need more warmth than flats would provide.
5. Yep. I work in a law firm. I need at least a formal outfit for each day. I prefer pants, but I have some skirts because there are some ancient souls in this industry who for some reason think women should wear skirts.
6. I have two signature accessories: earrings I got in Laos that are made with a traditional Laotian pattern, and an silver+amber necklace from the Art Nouveau period (it's over 100 years old) from my grandmother. The necklace is really my trademark, I wear it every day. I think having trademark jewelry is cool. People see that necklace and can instantly identify me. Plus it's a link to my grandma, which is a plus.
7. It's complicated. I have formal pants with butterflies on them that I wear with a pink shirt that wouldn't seem to combine, but does. So it's a context thing, we can't advise you here. But I'd say branch out, don't be afraid to try new things, and if it doesn't work, so what? Combine fashion, see what you get, and wear it if you like it. That's the most important part: YOU like it. Who cares what other people like? If it makes you happy, wear it, and let other people deal with their own emotions. Wear what makes you happy.