- Both of these fonts are not Freely-licensed. Wikipedia avoids putting any non-Free software on its servers.
- Webfonts were tried in the past on Wikimedia sites. It posed a lot of technical problems and was largely disabled. It’s possible that in the distant future it will be tried again, but definitely not in the coming months.
- You are only talking about the main page. The main page is different in every language. If you want to change its layout or colors, it’s actually quite easy to experiment with it on the actual Wikipedia and make a draft in your “userspace”. Convincing the English Wikipedia community to change to your design will be… hard ;) … but not impossible. But you need to look at each and every language when it comes to the Main page — they are all different.
- Just noting that you haven’t touched article layout, editing, discussions, user pages and maintenance pages at all. The main page is one of the most viewed ones, but it’s just the portal and the real content is in the articles.
- Unless I missed it, you didn’t touch mobile support at all, and the need for reading (and writing!) on mobile is growing constantly.