It depends on the type of fixture you have. f you had a ceramic fixture with a screw-in bulb, it might have been as simple as unscrewing that bulb and and screwing this in. For most other mountings, its just two wires to the ceramic base included in the package.
These lights are designed to screw into an old school porcelain or plastic light socket in the same amount of time as screwing in a light bulb. They also have an adapter to install to ceiling box so if there was electrical boxes in the locations you wanted to put these lights they are really easy to install. Also I have not heard of having to get a permit to change a light fixture (unless your state has a law that you need a permit to do any home upgrades).
Here's a link to Home Depot's posting of the specification for this ceiling light: https://images.homedepot-static.com/catalog/pdfImages/ed/edb25390-c7a2-4b00-a5e7-e55bd0e4b742.pdf Note: the specs say it is suitable for dry or damp locations; that being said you wouldn't want to use it where it would be directly exposed to water. I have 2 of these mounted under the eaves at the corners of the house and they are doing fine.
There should be a ground screw located on the mounting plate.
Information on the five year warranty is included further up on this page. The phone number listed is 1-877-527-0313.
If it is on a dimmer switch, that could be the cause of it flashing off and on. Home depot carries dimmer switches that can be calibrated to prevent led type bulbs from flashing, one might work for this light. Best to check with an electrician.
It will work, but you won't be able to use the pull string as the fixture will cover it. If the fixture has a on/off switch you can turn it on and off from the switch. I just screwed it into the bulb socket and use the wall switch.
Hi Max, does not tarnish or rust under normal conditions, but sure If you try really hard maybe you can get it to do what you want
Information on the five year warranty is available further up on this page. The phone number listed is 1-877-527-0313.