The prefixes -ajda - ocha and -uzga are often used in word formation to deride or ridicule.
Well, if it was one of these suffices: -ocha, -ucha (which you did not mention) or -och, -ocha, etc. I would agree with your explanation. But the suffix -UZGA just does not fit any word forming pattern in Polish language. This is a strange, foreign pattern.
I have a little risky theory about the origin of this surname, but before I am going to present it, here are the tools, so you can check it by yourself:
Grzegorz Jagodziński, in his "Gramatyka języka polskiego" (A grammar of the Polish language), [grzegorj.w.interia.pl/gram/] (English: [grzegorj.w.interia.pl/gram/en/gram00.html), writes about słowotwórstwo (word formation) here: [grzegorj.w.interia.pl/gram/i_slowotw01.html].
He presents an extensive list of suffixes (przyrostki) - ranging from -acja to -źń . Among them, there is -och and -ocha, but there is neither -ajda nor -uzga. However, knowing that -ajda actually exists in Polish, and considering that these two suffixes may belong to some dialectical forms, I double checked them via "Slownik Gier Słownych Scrabble i Literaki", [scrabble.krzyzowki.info/] .
The conclusion is that the -uzga words are these::
-uzga : only derivatives of the infinitives below, such as bl-uzga, obl-uzga
-uzgać : bluzgać, nabluzgać, obluzgać, zabluzgać, zbluzgać,
In other words, there is not a single noun in Polish language, which is formed with the -uzga suffix. The remaining words, are derivatives of the infinitives, all deriving from the verb "bluzgać". Which in turn derives from "bluzg" - but that's another story.
To be on the safe side, I checked the
-zga pattern as well. There are only eight nouns obeying this pattern - too few to be accepted as a generic word forming pattern in Polish language:
-zga : bezmó-zga, drza-zga, mia-zga, mo-zga, niebezmó-zga, pier-zga (this is actually wrong case), pramia-zga, ró-zga (+ -zga derivatives of the infinitives below)
-zgać : bluzgać, bryzgać, dzierzgać, nabluzgać, obluzgać, obryzgać, pobryzgać, poślizgać, poumizgać, pozadzierzgać, przedzierzgać, prześlizgać, rozbryzgać, rozwierzgać, ślizgać, umizgać, wierzgać, wślizgać, wyślizgać, zabluzgać, zabryzgać, zadzierzgać, zbluzgać, zbryzgać,
My conclusion is: the surname ROMUZGA is not of Polish origin. So what kind of surname is it? See the next episode for the answer. :-)