honestly, no. it's better save the money, and get better stuff.

if you must try out rgb, you can try tecware phantom elite. it comes with gateron switches also.
it's fine. it's only useful when you start playing with custom switches, so that you know the right springs to get based on your preference.

a rough estimation of spring weight range can be done with common switches actually, e.g., typing on cherry mx red (60g), gateron yellow (65g), gateron black (70g), and cherry mx black (i think around 80g). (linear switches are good for this purpose, because they are the most direct, with nothing in the way)

from your descriptions, i think your range should be gateron yellow and up.

Due to competition between Cherry and the Chinese clone switch manufacturers (although the word 'clone' is doing these Chinese manufacturers a disservice mind you, as a lot of these clone switches are often on par, and in some cases superior to those Cherry ones)

Note though different people has different tastes when it comes to key switches really - I'm currently enjoying typing on a Cherry MX Brown keyboard despite many enthusiast says that MX Browns are one of the worst key switches you can get

That being said, you should try to get a key switch tester, or even start off by buying a cheap mechanical keyboard and see whether you like the feel of the switches, or otherwise