I am not hugely fond of the idea of passing through deserts
I used to think that, but I discovered that they can be very scenic. More of a concern for you would be some extensive very areas of very flat and tedious scenery, whether it is grass or sand, such as if you were to choose a long trajectory across Kazakhstan You learn habits of carrying a lot of food and water on your bike when necessary. And need to ensure that your bike and luggage is capable of doing so.
hope it doesn't fall apart on the way
Reduce hope to the minimum and find out how to choose a suitable bike and be able to fix it. There's plenty of material around.
Bangladesh, Myanmar
Bangladesh-Myanmar border is closed. India-Myanmar border recently opened at precisely one location, and there is probably only one practical Myanmar-Thailand border (Mae Sot-Myawaddy) if you want to cycle all the way, though there are some other open crossings. Since the ability to cycle across Myanmar is very new, there is a lot of information available, look for it.
Also I was a little concerned with route, some of the middle eastern countries
Clearly with what is going on in Syria and Iraq you aren't going into the middle east at all, you are staying well north of those countries. But that is still OK whether you head N or S of the Himalayas, there are plausible routes staying well away from all that into Iran (for South) and former Soviet Central Asia (for North). In previous times you didn't even have to commit either way, because there was always the Khunjerab pass (open in summer) from China to Pakistan to enable you to swap, but an extensive part of the Karakorum Highway in Pakistan is currently closed to cyclists due to insecurity, though you can always get the bus.
Main problem for the south-of-the-Himalayas route, aside from getting that Iranian visa, is eastern Iran and the Baluchistan region of Pakistan, which are dangerous, and the police will probably make you take transport.
Former Soviet Central Asia is passable. Turkmenistan is a bit of a nuisance because it's hyper-authoritarian, isn't very interested in attracting tourists, and gives very short visas. But at least, unlike North Korea, you can actually cycle there. There are banditry risks in various areas of Former Soviet Union, as well as insecurity near the Afghan border, all documented if you look for it. And you need to think about the weather, especially if you want to travel any high mountains. If you are going north of the Himalayas then you need to be aware that Tibet is closed to independent travel, and there are some assorted other closed bits of CHina you can find yourself in by accident. But Sinjiang is mostly open so that is the way through, whether you come a mountain route from say Kyrgyzia or a lowland route from Kazakhstan.
