That's a weird attitude. Have a look at the Guides section, a lot of the guides were written by "pros". There are also quite a few people who are happy to share their knowledge of the game in casts and streams. I am certain this community (and the game) would benefit from the new players staying around and playing and learning instead of leaving because of the feeling of being in over your head.
I played a lot of EVE-online and the community there is great, there are whole corporations (clans) dedicated to teaching new players the ropes and most people are very helpful because they have all been new once and know what a handful that game can be in the beginning. This game has nowhere near the learning curve of EVE but the principle is the same.
Luckily, i think the people with your elitist view of gaming is a minority in this community.
I am not a pro and I dont know any tips or tricks, if I knew I would share
Maybe I can add an obvious tip: throwing a nade can be cancelled and when throwing a molotov/nade into a building, it can be a good idea to throw it at the exit instead, if you catch a squad on the exit its an alsmot guaranteed squad wipe since inf is clumped up when exiting a building