Simple answer, you are in the wrong. Should have entered on/before the 28th unfortunately to get 60 more days plus your 30. But you can still extend your exempt stamp by 30.
It's not illegal to keep your old passports but I wouldn't be surprised if you have to notify the passport service you have found it and cut the corner off
There is no actual limit to the number of tourist visas you can get but you MAY get denied if you abuse this for many years at the same consulate but you would probably get the warning stamp first
2 visa exempt entries by land. Unlimited by air. No limit if you buy a visa at a consulate in a different country before entering. Although you may get denied the visa if you live on tourist visa and exempt stamps for many moons
well i am no expert in that specific issue but if flying internally you only need to show id card not passport but i am not sure if immigration will ask fpr both at the border if you went the ubon - mkdhan route
