Are these elements modifiable?

[JustSomeUser]

I'd like to change the colour of, or at least have a coloured outline for, the URL bar.
Also, I'd like to be able to type paths into tabs.

I've highlighted these areas on this screenshot: https://imgur.com/a/siLvM

[highend]

Also, I'd like to be able to type paths into tabs

Type it into the address bar (valid for the current tab)...

[admin]

1) Not possible.

2) Right-click the tab header and choose "Relocate Tab...", then type.