How formal is the sentence below? Is this structure acceptable?
I can see it's a lovely place, too much hustle and bustle, though.
The phrase hustle and bustle is not marked as informal in dictionaries. Wiktionary defines it as:
A large amount of activity and work, usually in a noisy surrounding.
Though I'm particularly concerned about the use of "though" at the end, I also wonder about the overall sentence structure.
The phrase hustle and bustle is standard English. The sentence is standard conversational English.
The use of though at the end is used, however, to create a contrast with a previous statement.
So using registers like: formal, informal, conversational (spoken language) colloquial, slang etc., this one is conversational. It is not used in written language per se.
Here is a run down of the idea of register:
Here's an explanation of though as contrast at the end of a sentence. though in various positions_including end of sentence
The sentence is conversational, standard and this structure is very common.