Here are some answers to the last questions. Sorry I don't always check this post, so answers here can be a bit slow.
1. yes, set #2 is button height. I originally thought the on-button decals would be too small to make.
2. set #3 has evolved a bit from what you see here. I have added a few to the set, so I need to get a current version up when I get a chance.
3. I backup everything, so I can probably pull an old job to re-cut. Actually I've already done that set for a few others as well.
4. These stickers should never go bad. There are only a few things I can think of.
- eventual color fading. I've never seen it, but if they were exposed to sunlight a lot, they would probably fade a bit.
- They should be stored in a place with reasonable temperatures. If they get subjected to a lot of heat, it's possible that the adhesive melts a bit and sticks to the transfer paper. This just makes it a bit trickier to apply, but the stickers themselves should be fine.
- small pieces may fall off with abuse. These are pretty tough, but at a small size there is simply not enough adhesive to keep tiny pieces from moving. Again, I haven't heard of this happening, but it's possible.
beyond that, the actual vinyl is very durable. I also do RC cars, snowmobiles, race cars,...etc. The vinyl outlasts the RC car bodies, and the snowmobiles get branches scraped across them occasionally.
Hope that answered your questions.