There are many tweaks that can be done to configs depending on what mod you are playing but i personally find that just posting a config will not solve the issue for the commands have to be explained in what they modify.
For instance mouse sensitivity is really something that you can not comment on because 2 people might have same sens in game but completely different speed of movement due to the following factors:
nature of the mouse pad
mouse (laser/ball/optical)
mouse dpi
usb frequency
mouse drivers
os
which is why it is fairly hard to suggest a sensitivity.
As for connection settings these should help for those that are able to ping less than 100 on the server:
rate 25000 for refresh rate of the client which you will not really see physically - it feels a bit different and the map download from a server is faster because it gives a more frequent refresh of a seeder.
cl_maxpackets should be above 100 but normally even when it is 100, server equals it up to about 120-125 (for sure in cpma) for smoothness. Once again you will no really notice a difference unless you are using your own rockets/grenades/plasma to move - you will react later/earlier depending on the packets. You will definitely see the difference of a client from the side though - he/she will look choppy and harder to predict if packets are <50 whereas >100 will look much smoother.
snaps 40 instead of 30 just stabilizes your ping and brings it a tiny bit higher. Avg +10 I would say but keeps it a lot more stable which is useful if you are using railgun and lightining gun a lot and you are used to a certain distance of aiming ahead.
cl_timenudge is a predicting feature: 50 does not predict anything and actually shows your enemy late but making the movement very smooth - for good looking gameplay whereas -50 is where the game is trying to predict the client as much as possible and actually shows a little bit ahead of action while making the movement a little choppy. It does not affect your personal gameplay.
cg_truelightning is something people have really discussed a lot already - it is not a hack really because if you spec different ppl with different truelightining settings - you will see exactly the same thing. It is just a feature that modifies visible aiming for YOUR gameplay and makes it more comfortable - depending on what you like it to be: following every step of the enemy or let the lightning a little bit behind your xhair to correct your aiming mistakes.
Those are basic gaming commands - there are many others that i can not currently think of but i can sure explain and suggest if something pops up
