I could suggest a computer that meets nearly all you requirements with:
1) SIMPLE and easy to use
A very user friendly and intuitive interface, where you can (literally) figure out all the menus and functions in about 10 minutes without ever opening a manual.
2) EASY to read...I have mature eyes
An OLED display that is superb for mature eyes, and can be read from 18" to 15 ft away even with my 48 year old reading glasses dependent eyes.
3) Automatically turns on when it gets wet. This I must have, mine doesn't. Nuff said?
Automatic activation (not based on "wet: but rather "pressure" which is actually better as it won't activate or stay activated in a dive bag and/or if salt crystals bridge the contacts.
4) Nitrox capable
Nitrox mixes from 1% to 100% and up to 5 separate gasses pre-programed and on/off selectable on any dive.
5) Safety stop timer. Again, don't have this, want it.
Not per se, but it will display the current gradient factor telling you what advantage (if any) remains in a longer safety stop, or whether one is beneficial at all. That's better than just an arbitrary 3 minute or 5 minute stop timer as it gives you the information to make an informed decision of how long to stop.
6) Easy to find/push buttons. I can't remember what brand I borrowed from a friend, but the buttons were so tiny I couldn't hardly find them, forget about pushing them
Large, easy to find piezo electric buttons that cannot trap sand and won't stick.
7) I want to be able to customize or just turn off annoying audible alarms
What audible alarms?
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But I won't suggest it as it will cost you about $800. You can't always get what you want at a budget price, so you;ll have to decide what matters most to you and either cut features or