I do not know of any rules that are not flouted on a regular basis by virtually all English users.
I can give you specific answers but general responses on such a topic are virtually impossible.
English is not structured like most languages.
English is a very young language and is still very much in the evolution state.
This is compounded by the fact that English steals words and phrases from every language it contacts and cares not a jot if this brings in a punctuation problem.
The too is really surperfluous in this sentence and adds nothing.
This irritates me so much that I construct sentences so as to absolutely minimise my use of commas.
I consider a sentence with more than one comma to be inelegent. A sentence containing three or four commas is becoming unintelligible.