Can I cancel my accommodation used for my tourist visa and rebook without issues?

immigration will hunt you down. If you check into another hotel use fake IDs.. Do not leave your room without proper disguise.

I have been here 8 years and never once has immigration come found me, I suspect they've never looked for me. It happens sometimes but its rare.

If you do change rooms, hotels, towns, and you plan to get a visa extension, you will want to make sure wherever you go, they do your TM30 (inform immigration where you are staying)..

Yes, you can.