Do you have to follow exactly what the template or format that has been given by the conference or venue for publication? Would I be in trouble if I don't change them? If I changed it now, I would exceed the maximum given page just because of the indentation.

the short answer to your question is yes, you should follow the template. otherwise, what is the point of having the template? journals/conference organisers tend to get annoyed if you ignore their instructions.

If you exceed the page limit when using their formatting, that means your abstract/paper is too long, and you should reduce it to follow their directions.