I'm also very particular with this. It is very common rule when you're working on a project. A mistake in measure can be costly, undersize or oversize.
Nothing is wrong about wearing PPE, even if you're dealing with minor house repairs or projects.
Think about it, safety glasses would look better on you than an eye patch.
Me too, I don't have a clear idea of what you're asking. But i think it involves lifting stuffs with pulley and rope. There's really no problem with that, but you might want to consider where to attach the pulley, load capacity of the rope, as well the weight of the object being lifted...
If you're new to these type of project you will definitely need help. You might have some friends who knows reliable and trustworthy contractors. There's a great chance that you'll get ripped of If you make calls yourself.
The mayo definitely works. I've tried it on my coffee table and it took care of the water stain. Don't really know the science behind it, but it works.
Aside from treating the water stains you can also make some snacks with your mayo.