Lets start with answering some questions:
Does the advice the previous member gave me sound like it was good advice (that the power supply should be increased?).
Technically speaking, yes the closer the wattage the computer is requiring to the wattage the power supply can put out can increase overall noise of the PSU (Power Supply Unit). In my experience, most OEM machines like Dells, HP's, Gateways, etc... have noisier PSU's than some of the really nice custom ones I've dealt with. Also, they generally aren't of the best quality so over time they are sure to get noisier too. Another reason they get noisy is from dust and/or nicotine build up causing the fan to struggle and other components to run hotter. OEM PSU's usually are put in machines will little headroom from what the machine requires and what the PSU can put out.In short, it seems like good advice
, but a brand new PSU can be noisy as well if you don't know which ones are quiet or buy something not specifically made to run silent/quiet. For example, my PSU is dead silent, I hear nothing come from it... after all, it is called a "Silent Pro". However, a very good PSU in my parents machine that I absolutely love and is a great quality, has a fan that does exert some noise.
If so, did I increase the power supply too much?
No not at all. The PSU will only exert what the computer needs really.
Can someone offer some advice?
From your detailed description, it seems the sleeved cables probably just warmed up from being inside the computer and gave off a smell since they are so fresh and new. I have also noticed over time that new computer parts sometimes give off a funny smell right when I take them out of the sealed packaging. It is usually the spell of fresh paint/almost like spray paint smell.
I think as long as your system is running fine, don't worry about it too much. If the smell increases dramatically, something could be burning and take caution. Just keep an eye on it. Take note on how long you have left on the warranty as well if things get worse.
Hope that helps.