Frustration from tuning and constantly breaking parts caused me to walk away for a few years. The convenience of online shopping and a little more patience/maturity and I'm back into it now.
Watching youtube videos and reading a lot of forum posts really helped me get everything back in service and get my engines to absolutely rip. The only problem is there is plenty of bad information and misconceptions floating around out there and without having your own experience it can be difficult to tell who really knows what they're talking about and who doesn't. Particularly because people tend to be highly opinionated and sometimes confrontational about this hobby. You really have to take in all the information you can, draw your own conclusions and then just try things and see how they turn out.
Once you get a nitro engine to really sing and have some understanding of how it operates, it really isn't that difficult to keep it running nicely. Then down the road if you encounter some difficulty it becomes easier to troubleshoot problems that aren't related to the needles.