"Mike loves to go swimming; however, his parents won't allow him to go today."

Hello all,

I have four questions:

1.Are all these punctuation correct?Could you please correct me?
2. Couldn't I use the 'but' in the same way that 'however' is punctuated?
3. Is the sentence which includes 'however' considered as 'dependent clause' or 'independent' ?
4. And is the whole sentence considered as 'complex sentence'?

"Mike loves to go swimming; however, his parents won't allow him to go today."

"Mike loves to go swimming. However, his parents won't allow him to go today."

"Mike loves to go swimming. His parents, however, won't allow him to go today."

"Mike loves to go swimming. His parents won't allow him to go today, however."

"Mike loves to go swimming, however his parents won't allow him to go today."

So many thanks. Sorry for asking too many questions.