You are right that "стоит" is more like "you should"/"it is good idea to...". But I see nothing unnatural in "you should pay taxes, otherwise there will be penalization" (at least in russian). It sounds absolutely ok. Every "should" has it's "otherwise".I mean, to my English-speaking mind, it would seem more natural to use стоит in cases where one has a CHOICE whether to pay money or not.
So, replacements you are talking about, have no significant effect.
P.S.
Moreover, "should"-words (следует/хорошо бы) can be polite replacements for "must"-words (должны/обязаны).