#1.. 5 years old is NOT old fabric..lol.. I have some in my stash that is 20 years old and it does not affect the quality..
#2.. anyone who attempts a quilt with strips of printed plaids or rows of squares, is just asking for crookedness..
NOT because of their cutting abilities.. but because it is not usually printed on a true grain.
#3.. I'd advise you to be a bit kinder to yourself. I think you did an awesome job.
As to the quality of the fabric.. you use what you have.. that applies to all of us. and to what you can afford. I say just keep trying.. if you have the desire and determination you can do it. I frequently still use scissors to cut stuff out.. I also use all sorts of rulers, rotary cutters and a rotary ruler.. which is a combination device.. a ruler with an attached rotary cutter.
It is a timesaver for strips.