Trainz can stress a poorly cooled or underpowered machine, but kill it, I doubt it. The systems today have thermal and power shutdown built into them, or should anyway. An Intel CPU, I know, will throttle down its speed then shutdown if the system gets too warm. This can cause a program to crash, and perhaps corrupt the program data and the operating system when it happens.
If the power supply is underpowered, the system may not boot, or it may boot inconsistently. Remember to always over specify a power supply, or at least future proof it to allow for the bigger newer video cards, which today require two power slots usually. This can, and will cause a motherboard failure due to poor or low current regulation. This is the biggest culprit in component failure. If a component receives an under current for an extended amount of time, they will die due to thermal failure. This is caused by the part working harder than it should in order to operate the way it is supposed to. With proper current levels, and in fact consistent and regulated rails in a good quality power supply, this will avoid this issue.
To be honest, I'd look at other brands. BioStar is not the best quality company. Asus and even EVGA are much better. At this point I have an Asus mobo that is extremely stable. The EVGA quality varies and seems to go up and down depending upon the lifetime of the product. Near the beginning there are lots of teething pains, but at the end they become very stable.
All of the manufacturers suffered from a spate of bad capacitors. This was due to one of the cap manufacturers stealing some unfinished product formula from a competitor. This company sold their new "hot" product inexpensively on the market, every company purchased them, and effectively the market was flooded with bad caps. The problem was the product had issues that weren't worked out yet, and among the problems was a chemical breakdown and bursting. The capacitor issue did cause quite stir and put a few companies out of business. The problem is the cheap, and I mean really cheap manufacturers probably still have stockpiles of old parts, and will continue to use them until their inventories have run out. I say this from experience, having worked in a manufacturing company for many years, and seeing this happen!
The problem today is what appears to be a great price deal, really is not. The components overall are made cheaper and cheaper. This great for the pocket and wallet, but there's an underlying price to pay. This price is quality. The manufacturer will cut corners somewhere to still make a profit, and this is the area that suffers.
John