OK so I thought I'd try my hand at a guide for office
a. How to counter camping (especially CT campers)
I find the best method to counter campers is to beat them at their own game, so I use the scout.
b. How to counter Dak Daks (especially those CT campers in the window close to ct spawn)
Dak dak campers generally stay in one spot, because of the slow movement speed coupled with the fire rate. So the idea is to be more agile with movement, and to have a good long range weapon. For this I would recommend the scout.
c. How to counter P90 rushers
P90s are a great short ranged weapon, but they don't do quite as well long range. So the best option to counter this is to get something that can take them out before they get to close. My suggestion would be something with a scope, such as a scout.
d. How to be a better player on Office (Tips,etc)
Work out your own strengths and weaknesses, as well as what feels natural and fun . If you find yourself rushing all the time, pick a short range bursty weapon like the p90. If you prefer to have some accuracy but then also panic when there's multiple targets, go something like the AK47 or the M4A1. If like me, you like to stay wayyyyyyy back from the damage, but still run around and suprise people with a no-scope on occasion, I'd recommend the scout.
Also steal as many health packs as you can.
Especially from the top 25 rank players. Seriously. They don't need them.
Pythy.