You need to consider all of your variables, how much fuel are you delivering, consider your fuel pressure and the size of your injectors. Adjustable fuel pressure regulators are a must-have IMO. You shouldn't need re-mapping, because from my understanding all of the b-series computers come with a map that's good for a 2.0 liter set-up. Just manually adjust your fuel settings, and use the adjustable timing gears you have until you find a stoic mix, generally tuned honda engines run on the rich side, but nothing damaging or extreme if you do it right.

Retarding your exhaust cam 10 degrees is going to move the duration further down into the intake stroke, which has the effect of EGR, giving you something like 40% inert gas back into the cylinder, this will lower your emissions (it's how I get my all-motor integra to pass smog here in CA), but it'll kill your power and it might cause the "sputtering" you hear. Not really going to hurt anything as the piston SHOULD be moving away from the valves when it's that far retarded.

As for retarding your intake side, it's going to also help lower the compression in the cylinder by restricting delivery of fuel and air.

Another thing you must consider is that if you advance or retard your cams for the low-end, you're doing the same for the VTEC engagement, and to be honest, I don't know exactly what the timing characterstics for the secondary lobes on the VTEC cams are. You might already be so aggressive on the timing that you're really not going to notice a difference between your primary and secondary lobes after VTEC engagement. The only thing I could say would be that the more you advance on the timing from idle~4200, the more you advance further up the power band. But, I don't know if anyone will be able to just give you a number off the top of their heads.