Can you please post a bug (with screenshots, list of add-ons installed, and any custom browser css tweaks) to https://bugzilla.mozilla.org/ and CC :callahad in Bugzilla?
Those sorts of fit-and-finish bugs really bother me, and I'd love to figure out how we can fix that one for you.
Thanks for the offer. But I believe that the decision to remove the Forward button when there is no 'Forward' history was a design decision. Unfortunately, it has the unpleasant effect of resizing the address bar as well. So as you click through tabs, or click links, the address bar keeps resiing depending on the state of the history in that tab.
These 'design' decisions are quite silly IMHO. But I will find the original bug report and CC you on it.
Those sorts of fit-and-finish bugs really bother me, and I'd love to figure out how we can fix that one for you.