From my experience, I'd say apply a few extra coats of primer, letting it dry between coats. Eventually, the primer will fill in the differences in the patch and dry wall, giving you the appearance you want. You may want to prime the entire wall after the primer coats and then repaint. To be sure, paint the area just around the patch and some dry wall with the room color to see if it's hidden. If it is, finish the rest.
No, but sanding it can.
After mudding and sanding, primer is next, then paint.
Yes, they can, but are not as effective as good sandpaper.
You prime it with drywall primer.
Powder coated outdoor furniture must be properly prepared before painting. A light sanding will allow penetration by the paint. It is advisable to wipe the furniture after sanding and before painting.
Yes, but only if the joint cement is still wet.
A home handyman would need a drill, drywall tape dispenser, pole sander, sanding blocks, mudbox, drywall knives, mallet and corner cincher. In addition, one needs a shop vac to aid in clean-up.
Installing drywall repair kits is very easy, and can be handled by the vast majority of people. Patching, sanding, and painting are the main steps in the process and are all easy to do. It really depends upon your skill level and the type of kit you choose. Kits with backing require more mudding and that is difficult for the uninitiated. You need to choose a kits which is within your ability to use.
Depending on how bad the cracks are just filling them may or may not last very long. Sanding it all the way down to the drywall will make blending the new compound to hide the seems in easier but not completely necessary.
You will only need to purchase paint if you plan on painting the cabinets with color. Otherwise you will need sanding material. Stain if not painting them.
If your working on a car. This is the final step if you did body work on a car befor painting
You would not use sandpaper. You would use a screen. The sanding screens usually come in an 80, 120, and 220 grit.