Stop your ill informed scaremongering nonsense!!
A PSU is very unlikely to 'blow up' if it is pushed beyond it's capabilities not unless it is left in this overloaded state for a significant amount of time!!
This again is VERY unlikely to happen unless you like working with a computer that is completely unstable i.e a PC that keeps on crashing and restarting
When more current than that of which can be supplied is demanded the PSU's output voltage simply drops (current & Potential Difference (aka Voltage) are
inversely proportional)
Once the voltage drops below spec it causes the computer to crash!
No bangs, No fire, No house burning down

Obviously damage can occur to the PSU if you leave it running in this cycle for a significant amount of time, but as I said above only an idiot would do this!!
Simply identify that the PSU is not powerful enough as the fault (by swapping out for more powerful PSU and observing the PC become stable) and save the old PSU for a less current heavy rig!
Obviously this is being sold as a package and unless you start chucking in DUAL top range GFX cards and other high current draw components then I am pretty confident that the supplied PSU is more than up to the job!!
Also I don't quite understand how the 'RAM was too fast' ???
You do realize that RAM can be run at speeds lower than that of which it is rated!!
I could happily place 1066Mhz RAM into a mobo that only supports 800Mhz RAM and it would simply and happily just run at 800Mhz rather than 1066Mhz!