@Mattie.B There are likely multiple issues to sort through, from what you reported.
1. Your plugin issues may stem from one or more older plugins that may not run properly in X3. Once the X2 and X3 software gets stabilized, without adding your plugins just yet, we can collectively look at which plugins it all falls apart on, and get you fixed back up.
2. The plugin manager from X3 replaces the one from X2, I think (not sure, but think so). It may be that you need to do COMPLETE removals of both X2 and X3, including registry keys and hidden folders, followed by installing X2 again to get it back working for you.
3. Make sure your Windows maintenance is up to current levels, as some X3 routines require certain minimum levels for redistributable routines and such.
4. Independently of the other issues, I recommend you run both DPC Latency Check and LatencyMon to make sure one or more background service or device driver is not interfering with audio streaming on your laptop. WiFi is one that can cause issues.
So, hang in there, lots of potential help here, and once you do get stabilized, you should be fine, as there are lots of folks running X3 successfully at the moment. (I do not know if the X3c reported issues have been resolved yet, I am running X2b with no issues).
Bob Bone