Hear you on how horrid it is to watch a parent's clutter ordeal! It really is better to live with a minimum of "stuff", and to choose what to put into your home really really carefully.
#1: This is an emotional issue, not a clutter problem. Three things:
a) the people who gave you those gifts would be horrified to know that they're cluttering up your house. Do the kind thing and regift/pass on these items to someone who will find joy in them every day.
b) the people who gave you those gifts love you. Their gifts are just symbols. They will still love you even when the symbol is no longer there. People who really love you, love you for YOU, not for what you do with useless gifts.
c) anyone who gets miffed by you giving away a gift that you don't have use or space for has emotional problems that are not your affair. If you offend a person who has this kind of attitude, that's not a reflection on you, but rather an indication that they need to seek help. (i know that sounds harsh, but seriously, it is the truth!)
#2: I'd suggest putting your notes into date order (or topic, or whatever --depending on what would be most useful to you), and putting them into low-cost storage in your area. They'll be perfectly safe and you can access them whenever you need to.
A more labor-intensive solution is to digitize your notes (either by simply scanning them, or by extracting them into searchable text format -- which is possible, though obviously more expensive since you'll need specialised software or a service provider for this) and store them on a Cloud server or similar.
There are a few books out there that help you deal with the emotional side of clutter control too. Basically, it's about changing your thought habits from being oriented towards "stuff" to being oriented towards "people" or "experiences". "Stuff" is ephemeral. It will fall apart, break, annoy you, be useless. But people and experiences are things you carry with you in your memory forever. And when you have a house full of "stuff", you have less psychological space to enjoy the people and experiences in your life. Hence, get rid of your stuff