Welcome to our forum and the hobby!
As to pasteurization, I can't be much help. I pasteurized the first time, and not since then. When I did pasteurize, I did the whole batch. I had a brew kettle that would handle the entire 3 gallon batch.
As to sterilization, I can at least tell you what I do.
When I clean my equipment, I first wash and rinse it all with dish soap with the hottest water I can tolerate. I then rinse it all in a solution of sodium metabisulphite, and then rinse that off with boiling water.
It's really not as labor intensive as it seems.
Get set up ahead of time. If you are working in the kitchen, take the time to do a good thorough cleaning and sterilize with a light bleach water solution 10% will work nicely.
Make up your sodium or potassium metabisulphite solution ahead of time. The directions should be on the package. I keep a 1 gallon jug of the solution ready for use.
I start a large kettle of water to boiling while I'm cleaning the kitchen and washing the equipment. It all goes quickly when you've got your system down.
One thing I do as a precaution is to move all the vinegar in the kitchen well away from the area I'm going to be working in, and double check the caps. In our kitchen the most probable source of contamination would come from Acetobacter aceti, the bacteria that produces vinegar. Don't try to use an old McDonalds pickle bucket as a primary. You'll be very likely to make a nice batch of honey vinegar.
Good luck and keep us posted on your progress.