Some of the changes which occurred in OTL ROmance languages would not occur:
- obviously Germanic loanwords would not abound
- also, the way words changed (you gave some examples) would not occur if spoken Vulgar Latin were not the only or predominant means of language transmission.
But other changes which occurred with OTL Latin, Spanish Portuguese, and, to some extent, French might occur with Latin in a surviving Roman Empire, too:
1) the simplification of grammar
2) heavy Greek influence
As for 2), both OTL and ATL the influence of Greek comes basically through academic / scientific language.
As for 1), all Indo-European languages began as highly synthetic languages, where all the grammatical information was stored in long and complicated suffixes at the end of words. Then, the stress moved forwards within words to the first syllables, with the result that all the information tended to be in the mumbled, unstressed parts of speech, which was impractical. Indo-European languages have therefore undergone a millenia-lasting development of abandoning suffixes and transferring the information stored there (e.g. about case, gender, tense, mode) into separate words.
E.g. the present perfect of "to have":
In Latin, it was "habui" (of "habere"); in Italian it became "ho avuto", in French "j´ai eu", in Romanian "am avut").
Or the cases of nouns:
In Latin, it was "domus, domi, domo, domum, domo"; in Spanish it became "casa, de casa, a casa", in French it became "le maison, du maison, à la maison".
This, I suppose, would happen in some form or other to a surviving Latin, too.