Nobody can say if the linux will run. We can just suggest which linux suits you but wether it will work on your hardware not really isn't important, as your laptop should run every normal distro.
Normally localhost should always resolve to 127.0.0.1 as default O_O
This sounds like an issue with an dns server, as it should only take a couple ms
XAMPP loads a lot of stuff you often don't need. I personally use docker virtualized webservers or run it in a linux vm.
As you are starting out Ubuntu or Mint(which is based on Ubuntu) is a greate choice since they are pretty easy to use for starters and most programms you can think of as easily aviable. Regarding MS office, this isn't aviable in Linux but there are two good alternatives with Libre/Open Office...
Yes and no, you can run linux without installing anything on you harddrive, but often with some form of limitation. You can also install a linux alongside your windows without deleting it, but this will need you do make some spache on your hdd.
The usb stick will get formated during this, so...
Sure^^ As linux is really lightweight(most installation files are only 2gb). There are versions of nearly every distribution you can simply put onto an usb stick. Depending on the distribution, changes you do, like creating files or editing settings, are often not saved but it's a really good...
Yes you can, I have run Linux on my old tablett(original windows 8) for a long time, as you often need less powerfull hardware. I always depends on your distro. You can install something like Lubuntu with only 500mb of ram. It really depends what you want to do with it, but at least some form...