When I first flew my Javelin, with CG right on the spot recommended in the instructions, the plane flew way too noseheavy. I plotted the wing to get 33% of mean aerodynamic chord, and came up with 6-1/2" back from leading edge (instructions were for 5-3/4"). I eliminated noseweight and rebalanced at 6-1/2" back and the plane flies great. I could push it back even further, but I'm very happy where it is. The plane is not at all touchy at this balance point--nice and smooth on all inputs. Of course I have very conservative throws on ailerons & elevator, plus 50% expo on these controls. My engine thrust offsets are strictly what comes built in to the firewall. I have thought about messing with side-thrust offset, but so far have been content to play with throttle to rudder mixing. Vertical thrust is fine right where Cermark has it--no sinking or ballooning when I go from full to chop throttle or vice versa.

I set my elevator trim so the plane will come down slightly with no elevator input on straight & level. So I'm always touching the elevator stick--just a touch of pull for straight & level upright, just a touch of push for straight & level inverted.

The Javelin is susceptible to having the wing incidence vary somewhat from one model to another. I notice when I tighten my wing hold-down bolts, the "fuselage" part built onto the bottom of the wing is not perfectly flush with the fuselage at the trailing edge of the wing--it sets in maybe a little less than 1/16". If having these surfaces perfectly level is zero incidence, then I'm probably at negative 0.5˚. I'm not recommending that to anyone, just observing how mine went together.

I know a Master class pattern flyer with lots of experience on the Javelin, who's very happy with the recommended CG, and that's where he flies his. When I asked him to show me straight & level inverted flight on his Javelin with no elevator input, my feeling was it came down a lot faster than I like to see. That would imply nose-heaviness to me.

My first recommendation would be to rebalance your plane at 6-1/2" back from the leading edge. 33% of MAC is not tail-heavy, it's very close to neutral. My second recommendation would be no change to the vertical offset of the engine--just mount it straight to the firewall. Side offset--be my guest, but I find it easier to fiddle with throttle to rudder mix, which I set up to kick in only above 3/4 throttle. The rest of the time I'm flying the rudder all the time anyway.

For what it's worth, I have a YS63 in my Javelin, with fuel tank under the canopy (just forward of my CG). I love this plane. Everything I am capable of, it's more than capable.