Do I need to report to immigration and show a TM30 if staying in different hotels in Thailand?

If you have a DTV you not need too. As you can stay upto 180 days so there is no 90 day reporting

Your DTV, did you get it for education?

Don't sweat the TM30 too much, especially if you are travelling around the Kingdom. The odd day here and there will make no difference whatsoever.

When you need ether an extension or a 90 day report make sure you have a TM30 then. TM30 is the responsibility of the owner of the property that you stay to do. Unfortunately there is an anomaly meaning that if it isn't done and you need a service from immigration (visa extension or 90 day report as examples) you are the one who gets a 2,000 Baht fine. So my advice would be when you need to go to immigration make sure you have a TM30. Most hotels will just give you a print out.

I just printed out the code that they sent you in your email. Take that with you to immigration and also take your passport and your boarding pass. That’s all you need. You’re good for multiple reentry unlimited. For the next five years. When you go shopping and use your credit card, bring your passport and of course your Visa card. Very limited places to use American Express. 

When you attend immigration you need only the most recent TM30. Any others you might as well roll up and smoke

For the 90 days report you can use the most recent TM30, you don't need all the previous ones (tho each hotel is obligated to file one, yes).

No, you don't have to do anything within the first 90 days, if you're staying in hotels.

The hotels register you as a guest in the immigration database every time you check in to one.

But you have to do a 90 day report if you're staying in the country for 90 consecutive days.

You have to do this in person the first time, which resets every time you enter the country.

Just show your latest tm30 prior to doing 90 day report

Yes on both accounts.

You need to do the 90 days reports. The hotel is responsible to file a tm.30 within 24 hrs after check-in. Most hotels do that online. Just make shure the hotel makes a tm.30 and ask for a copy/screen shot before you go for the 90 days report.

Yes and yes

If you stay 90 days consecutively you need to do a report on your stay.