I would like to reiterate point 6 as I made this mistake with a past business. I was filing the quartly sales tax reports with 0 dollar sales. THen I just stopped.

4 years later me and my partner get a letter from the state comptroller wanting to know why we hadn't been filing. We were looking at several grand in penalties. When we went to the audit thankfully we got an understanding auditor who was able to close the account retroactively and remove the penalties.