Im going through the same stages and I found out that rwd manual is certainly different than fwd manual.
Thus i dont have any problems going in reverse LOL.
I found that im just under 1300 rpm when i feel it engage nicely and smooth enough so that it wont stall. I tried the bliping method and its a bit sketchy, feels very abusive on the clutch too (works great on hondas tho). I think a lot of my problems came from the RWD difference, i never had any issues with fwd before. The Z also has a terrible tranny IMO, my friends bmw 328i is almost 10 years old and its very nice and smooth in all gears, especially at starting. So dont stress too much, you just have to get used to it.
I found on level ground its best to slowly release the clutch without the gas but have it ready to go and then as you feel it grip give it gas bit by bit. So i vote method #2 for normal flat driving and in theory option #1 for uphill or slight slopes, but lower the revs, even around 1500 should be fine. Just dont take forever riding the clutch, its a nice way to burn it out if you do it for too long/too often.
If you have any friends with motorcycles/atvs, they can teach you about clutches and you will learn a lot quicker since its a hand clutch. I learned to drive stick on my atv and they have so much torque you can get going uphill with no gas
Now those things rip off the line. Wet clutches are also more forgiving.
I learned to get a better feel of the Z by driving at night around my neighborhood and following all traffic laws, stopping often and starting as if there was traffic around me. I had the same issue as you where i found even shitty little cars would take off like bullets vs my 350z. Also try to get out of 1st as soon as you can
Another tip is trying a different pair of shoes, as stupid as it may sound, older shoes or ones with a thinner sole will give you a better feel of the clutch engagement. My work out Pumas were ideal when I was getting used to it. After a few hours you will do it by feel and sound.
Im getting better but still learning, this is after i drove it 800 miles from the dealer.