Acomputer is very fast and efficient when you have more then 8 gb of ram and when you have an i5 processor plus don't forget the ssd which is good for downloading and for little storage. i built 2 gaming computer using an i5 processor, 16 gb of ram, asus h110m-e/m.2 - motherboard - micro atx - lga1151 socket - h110, i use an 1080 ti gpu, i have 1 tb of storage, and use a kingstone ssd a400 with 228 gb for download speed, 600 power supply, and use a nzxt case.

You must have a sound card

For question 1, i'm a bit stuck between serif fonts or large enough type to read. serif fonts are good fonts to use because their easy to read. but you also need your type be large enough to read. if i had to say what you need to consider most important, i would say d is the answer.  for question 3, i believe the answer is d. it seems most appropriate to do that. on every page or every other page would be too much, and only on the contact page just seems inappropriate.  for question 4, it's probably a. by "color scheme" it doesn't mean just one color, but a set of colors. colors that are complimentary to each other. having too many is too distracting so it's best to limit it as much as possible, but not to the point where your website looks dull.hope this !