Traveler AA5 pilot reported an NMAC while on the fist approach and on the second approach a helicopter was observed hovering on the final approach course.

Narrative

This incident actually involved two incidents and resulted in breaking off two approaches just prior to entering IMC conditions because of serious traffic conflicts; one of which required evasive maneuvering. This is an ongoing issue with the vectors provided by ZZZ into ZZZ1; which really is a Class C level busy airport with Class D status because it is GA only. This kind of problematic vectoring does not happen with FAA facilities like ZZZ2; ZZZ3 and ZZZ4 and it is high time that ZZZ1 and ZZZ5 have their airspace given either to ZZZ2 or ZZZ4.This is even a bigger problem with traffic coming from anywhere other than the east/southeast on straight in approaches; but there are still issues even with straight ins.I departed ZZZ4 on an IFR flight plan; because the weather did not lift as expected and also was too low and thick to safely perform a visual approach into ZZZ1. As such; I opted to remain IFR and take vectors for the RNAV Z ZZZ6 approach; which I have flown hundreds of times and am very familiar with. The airplane was on autopilot and performing as expected. ZZZ was giving acceptable; though rather late vectors and keeping us high. When finally vectored to final and given an altitude; I needed to disengage the autopilot to maintain a stable profile because of how tight the turn to the final approach course was. I was making this turn when a relatively large; light twin - possibly a C421 or 414 - flew directly under us at 100-200 feet below and my passenger spotted them; with urgency in her voice. I immediately started a climb and leveled off on the heading I was on; as I was not yet in IMC conditions and told ZZZ that I was taking evasive action and needed vectors and an altitude for the approaching terrain). This aircraft was VFR and not talking to ZZZ or apparently on flight following at all; which is another major problem with how operations are handled by ZZZ; and was apparently attempting to scud run down the final approach course to Runway XX potentially even shooting their own IFR approach without clearance.I was then given vectors back to the final and these vectors were relatively stable; but my avionics and ATC gave me a traffic warning for an aircraft directly in the final approach course that apparently was under the cloud layer. This was apparently a rotorcraft that was waiting outside the Class D for SVFR clearance; directly on the RNAV final. As I could not see the aircraft to avoid it and the altitude put it entirely too close to the glidepath profile; I told ATC that I needed to be revectored for the approach. Finally; I was brought back around and the rotorcraft was told to vacate that particular area by ATC and I was able to both spot them and commence an approach to land.This is a very serious; ongoing problem for IFR and VFR aircraft operating into and out of ZZZ1 and ZZZ5 but especially for IFR aircraft operating on radar vectors into essentially a no-man's land and into IMC. The only fix for this is either for ZZZ to allow and encourage flight following from the ground out of ZZZ1and ZZZ5 or for to give up the approach airspace to better equipped FAA controllers who have far more training. ZZZ didn't even give us a location on that first aircraft - any of the FAA facilities mentioned would have vectored us away long before this happened or had tower tell the aircraft to move away from the approach.