After you hypothetically make all these changes, you will end up with a different cue which might not be the cue you want to keep for the rest of your life. You can keep it as a backup or sell it and buy one that you like the weight and balance of. Or quit being a little bitch and use it as it...
Blind tests have shown that players cannot tell what joint there is on a cue when it's hidden. Any joint that is solid and tight will work. Metal joint vs G10 will have an impact on the weight distribution but it's a preference there's no right or wrong. If you're installing it yourself go with...
The entire butt will need to be retapered and refinished it will be expensive. Many cases will fit a 31" butt or shaft that's the more obvious solution.
Your logic is flawed. The maximum contact between the tip and the ball is 60° of arc. Less than that you would have less than ideal contact and more chances of miscuing. More than that doesn't offer any added benefits. The nickel (for thicker shafts) and dime (for thinner shafts) approximate...
Layered or single? Triangles are taller than most if not all layered tips. Also if you take a new 14mm tip and cut it to a lower diameter, the proportion of height to diameter would change lot. I can't imagine a scenario where you would need a taller tip than what's available.