I still don't know how to rephrase dabbling correctly. Can you check if everything is OK? Thank you for helping
1)He thought there should be sea-police upon the Haerwich-Holland ranges since that sea stretch was constantly overrun by pirates.
2) He was expert at dabbling (synonym) in exchanges. He was such a shrewd businessman that nobody knew he was heavily in debt.
3) He was pompous in administration and an excellent fellow, too. Chaucher doesn't know his name.