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Increasing compression might increase fuel economy. I say might because its not a simple yes/no answer. In an ideal engine with no other changes, increasing compression will increase power output and efficiency. However, there is no such thing as an ideal engine in the real world. Increasing compression has effects on preigintion and just ignition timing in general. Usually, with high compression you need to retard timing at higher engine loads so you can avoid knock/preigintion. This reduces efficiency. IMO Honda makes great engines and I'd be a bit surprised if you could eek out a noticable gain.
A shorter duration cam would give you more lower rpm power while sacrificing high rpm power. Your vtec helps negate this though. This also will return better mileage, and this can be a sizable gain. The Metro guys with XFI cams see a fairly decent gain.
IMO leave the engine alone. Do a compression test or leak down to see if you really need a rebuild. "Feeling" you need to rebuild an engine is just not possible. There are tests you can and should do to be sure.
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