2004 Nissan 350Z oil consumption

2004.5 350z with 100, 00 miles that burns at lot of oil and is progressively getting worse (one qt synthetic per 150 to 200 miles + -). Although it gets great gas milage on the road of 29 to 30 mpg. Engine seems to run perfect and has smooth sounding lope although I notice that there is slight valve pinging when accelerating but only for a second or two at a certian low rpm while accelerating to higher rpm and I think only when pushing it.

Smokes when start up and if hold foot
on brake and rev up it produces smoke like crazy.
When just driving around does not seem to produce smoke but when slowing down to take corner or giving it some gas after slowing down in traffic produces some smoke.

Started skipping the some time ago, bought engine analyser, noted cyl 4 misfire, pulled plug, covered in oil and worn out gap, replaced. Again recently, cyl 4 and cyl 3 reading misfiring, pulled both plugs, 4 again covered in oil but 3 just worn out not wet at all.

I have heard bad things about some of these engines (mine is VQ35DE stock) valve stem wear. Nissan is mum on this subject although issue TB on '05 and '06 MT for block replacement. I am out of warrenty but expected engine to last more that 100,000.

Dealer said to just buy used engine with 20,000 miles for $4000 installed and don't try fix engine cause other so called leaks might occur in other areas of engine not fixed and best to get used engine. New engines installed from dealer $11,000.

Suppose need compression and then flow down test as per some of your responses to others.
What is my problem. Should I go through all that or just get used engine.

Thanks,

Charles