The bad stuff you heard about is cumulative Thailand. The explosions from protests are old news, but last year we had a bombing. The mosquitoes ... when to zika spreading the world it's like nothing. Regarding flooding, to put it politely ... Thailand's in a HUGE drought. Bangkok and within at least 100mi surrounding. Our rain season has seen maybe two rain storms. Ok, so now let's get to the pros and cons in my opinion, some based on what I hear some based on my life here some based on your post.
Cons. Is there corruption in police though? Yes. Or maybe a huge language barrier. Yep. For example I called the fire department to report a fire and they hung up on me twice because I didn't speak Thai. Imagine my house now burning down, LOL. Is the heat almost unbearable at times? Yep. For the first time in my entire life I am running air conditioners and fans 24/7. Large public transportation network made up of the sloppiest infrastructures combined possible? Yeah!!! And how about the wages? Low to medium (many convince themselves otherwise because they compare to an incredibly low living cost which I'll get to in the pros). So if your company is paying you a Canadian salary, awesome. How about the Mafias operating in the outright public (i see this way more prevalant down South, I had personal experience with this on Koh Tao about 4 years ago as well). Or Lese Majeste / bejng unable to air greviences or even opinions against the King - it is literally against the law with heavy punishment. With that said, freedoms are less and less AT THR MOMENT due to a military coup. A lot of expats are worried (in my experience) and those that arent have either invested their life into Thailand and CAN'T worry or will argue you no matter even if you're making a good point or not (typical expat in Thailand). Also, big one, road safety is something I hear and read about a lot but as a motorcycle / scooter driver my only two incidents (small enough I wont even call them accidents) they were my fault. Two big ones I think effected me on a personal note since I've been here are the abuse of religion and the development of the country (3rd world) as you mentioned, but I almost found the latter inspiring. The religion, it's sad because Buddhism is so well respected in the Western world but living here I've heard more about corruption in it than I have heard legitimate stories of priests and children. Not that I'm a religious man either way, I just thought that Buddhism was respectable in many aspects and very much explains a lot of Thai culture (for instance, Thai people being unable to ever tell time). Regarding development, I should notate that I've lived in China as well. I'm not new to people picking my trash for recyclables ... But to not have a legitimate recycling program and then offer polypropylene cups at the movie theater? The Chao Phraya river looks like a dump thanks to smart (sarc.) ideas like that. Or how about the lack of innovation (for instance : solar is barely coming, no one wants to invest for the last two years even with gov subsidies), Houses are poorly insulated so the grid is overhauled and energy is wasted, etc. It hurts just to talk about. And like I said - this is the shit that's inspiring when you think enough because you think "how can I make a difference'' besides throwing money or Facebook complaints at a problem like we do in the West. Those are a bunch of things that i find cons of Thailand/Bangkok. So we've done many negatives ... Let's do some positives.
As I said, INSANELY cheap living cost. A soup that costs me $8-10 in the US costs me $2 here. A full dinner with friends at a fair / nice place can be as cheap as $10US to $30US. I don't drink so that number is quite low, but beer is also cheap. Hard liqour is a but more expensive and almost not worth it here, but that's on you. Either way, the booze adds up fast while any and all food costs next to nothing. Next ... The shitty transport I mentioned. If you don't use the trains or busses or scooters, there are taxis. Taxis are a scratch of what they'd be in the US (I haven't been to Canada in long enough to not compare to Canada or in CAD, sorry). Anyways! Rent is cheap - for instance I have a two floor, 2 bedroom/2 bath townhome which was built just last year and costs less than a studio apartment in the Chicago suburbs. Id say thats pretty decent especially since that saves a lot for bills, travel, food, etc. Ok, now the next one is subjective and should not only be taken with a grain of salt, but you should understand that it very much depends on the person / situation. But Thai people, in my general experience, are nice and in many times, playful. Or many times they can be very helpful. I, for instance, have many Thai friends who maybe surprise me on my birthday or come to my house when I need to translate something or whatever helps my Thai life easier. I should say I remember the bad experiences, but I know I've had more good than bad. Next! Bangkok is a SEA travel hub and connected well to others. So if maybe you want to see Vietnam, Indonesia, Malaysia, Philippines, Laos, Cambodia, Myanmar, China, Hong Kong, Japan, etc ... You can do that all from Thailand, cheap and easy. Especially with plenty of low-cost, long haul flights like EasyJet and AirAsiaX or EastarJet or more. In my two years living here I've been to many countries in the region and wish I could afford to see more.
If it's only for 4 months, I say look beyond the negatives, get some experience and enjoy your time on this planet. If you had a 2 year contract ID say go elsewhere.