I think a lot of the problems are software and browser comparability. The E visa application site runs fast and smooth from an Android phone.
The number 1 problem though is the pending files in the folder. YOU CANNOT do anything or make changes with a new application if you have these files sitting there. You have to either make the application or delete them.
I believe because it is web based, that it was designed this way or the system would eventually crash due to overload of dead files on the server.
If your getting a single or multiple choice selection when applying for 'Long Stay' you have files sitting in the pending application folder. You MUST clear and delete them first and then apply
The @ your having a problem with is a software comparability issue on your keyboard. There is another keystroke you can use in place of @ but I cannot remember what it is. You will need to Google it
what happens is each time you try an application, it will store in pending applications BUT it will stop you choosing another option and will default to the previous application. If you either don't recover the application from the folder and carry on or delete it, it won't allow you to choose other selections.
It's a pain but once you've cleared everything, it should be fine
Immigration won't ask for a ticket out when you extend.
As for your bike, Thai customs are working out how many thousands of baht they are going to charge you on customs clearance charges, storage, VAT and Import duty.
ok I understand now. Yes the system only allows you to enter the same visa type as they expect you to be travelling together.
If you wanted to apply for different visa types on the same application, you need to register as an agent. Then as a travel agent it is possible. I have no idea what they request though to register.