Questions about the ATLAS tree

Just finished the main story up a bit ago and have very little clue where to start with the ATLAS tree. I've been doing some heists, a bit of Delve. I'm also interested in picking up things like tainted currencies.

I'm not sure of two things. How thin you can spread yourself on the path. Should I just choose one thing or can I spread myself out without an issue. And two what things would improve my chance of picking up tainted currencies or if it is even worth it (heard they had been nerfed).