The #star-button selector is the same. I'm not sure about the RSS button; I don't see that one.

The Stop, Go, and Reload buttons now share the same space and which one displays is determined by the status of the page and the URL bar. Their individual selectors are #urlbar-stop-button, #urlbar-go-button, and #urlbar-reload-button. (By default the #go-button is hidden.)

Last year, there were discussions on this forum about customizing the toolbar to move Stop and Reload to the left of the address, bar, which separates them from the Go button. I haven't searched for those to test whether it still works.

The RSS feed (Subscribe) button is a regular toolbar button and no longer located in the location bar.
So you do not need to hide that button, but you can drag it off the Navigation Toolbar in the toolbar palette if you have it visible.

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

whoops. i was editing a portable firefoxes .css intsead of my native installed one but still couldn't get "go button to work. after a bit of googling i found a solution

#urlbar-go-button {visibility: visible !important;}
#urlbar-reload-button {display: none !important;}
#star-button {display: none !important;}
#feed-button {display: none !important;}

although i wish i could set the go button last instead of first (go arrow, history dropdown, refresh)

but i see what you mean with stop/refresh being separated from inside the urlbar

edit: oh i see about url-go-button and url-refresh-button now. thanks