"expectans expectavi Dominum" means: "Waiting I waited for Lord", so you should think over again how to convey the expression "com paciência". This is easy (almost the same in Latin!)
Maybe not. The Bible is a (relatively) fixed text. I took it straight from a Latin bible. In this case, I assume "expectans" is translated as "with patience" (i.e., "com paciência".
You shouldn't be suggested by official translations so much, stevo... They are often very literary and with context they can be understandable, but without context (like here) they are not anymore...