Is it normal for the Lessee to pay for land taxes, structure usage taxes, etc, etc in a Land Lease Agreement?

No not really, but again it usually boils down to negotiation. If you are getting a great deal on the rent, then why not? However if its not so great...

Lessee will pay the taxes, samesame as in the west. You pay either buried in the rent or visible.

The good news is that property taxes in Thailand are negligible, not the cash grab to support overpaid municipal employees that they are in many western countries.

I understand that there is a 12.5% tax payable by the landlord on the actual rental amounts OR the assessed gross rental value of the property (whichever is higher). BUT many landlords cheat on this tax and dont pay.... (some landlords who actually do pay the tax, break up the rental agreement into two, one for rent and one for "services" or some other fiction, to reduce the tax payable)...... I dont think this is a negligible amount....