Landlord Failed To Provide Itemized Security Deposit Breakdown And When Challenged Threatened To Take More Money Out Of It

Location: Massachusetts
After a recent move, my landlord returned less than the full amount of my security deposit. I sent an email inquiry about the charges and he replied with two items, a cleaning fee and another fee, totaling about $800. I emailed him back, contesting the cleaning fee, because blanket cleaning fees are not legal in Massachusetts (and we had cleaned before moving out) and asking for proof of his payment for the other fee to make sure that he wasn’t overcharging us.

He replied saying we were correct to not be charged this fee, but that he would instead be charging us around $1700 to repair floor damage (it was scraped at one point during our lease when moving a bedframe), and threatening to stop payment of the security deposit check. He has not acted on either of these actions since.

I have pictures before the move-in showing some preexisting floor damage, as well as a video from the move out showing the state of the apartment.

This was all done within the 30 day window of our moveout, which has since passed.

I’ve contacted the attorney general's office through consumer complaint form and they said they can attempt to get him to settle for the initial amount(but he can just not respond), or I can attempt to take him to small claims court; they also mentioned that with either option he may attempt to get the $1700 from me. This leads to my questions:

Do I have adequate grounds that this is worth pursuing? If the landlord is doing this to me he is almost certainly skimming others' security deposits and it feels so bad to me that he can threaten to make it go away.

Should I be afraid of his countersuit if I pursue? I don’t think he replaced the floors and is just using this to threaten me into complacency.

If I do claim this through small claims court, should I claim it with a $50 ($501-$2000) filing fee or a fee required for the total security deposit?