-20dB for everything except the kick? How is anything audible/ how much headroom do you have?

Here's a little "gain-structure" guide that you could try using. Just remember, there is no perfect formula for gain structure and you should adjust everything accordingly to what you believe best suits your track/style

Volume
       a. Kick = -9dB
       b. Vocal = -12dB
       c. Leads = -15dB
       d. Bass = -18dB

Thanks! I'll give that a shot, Ilan Bluestone says he builds his tracks like that with the kick near 0 dB

That's the best part about music production. You can do what you want, what you like, or how you like to do it. Everyone has their own style and methods so don't think anything is necessarily "wrong"

What would you leave the pads at out of curiousity?

Depends on what you're trying to create, but more often than not they would be less audible than the other instruments in the mix.   Just to throw a number out there, -15 to -20dB. Maybe some stereo separation to push them to the back too. One of my tracks I actually have a pad at -13dB.

Generally I use pads as a background so they do not need to be "in your face" loud. But remember it's all relative to what you want to produce, and what you want your music to sound like.

Volume
       a. Kick = -9dB
       b. Vocal = -12dB

For me, I would have the lead vocals somewhere closer or even equal to the kick. The vocals in the song are the most important thing for me, unless it plays a smaller role like it's a sampled chop for instance. But if there are full lyrics involved, I definitely want to make sure that those vocals are upfront. I always feel that if you can't her the lyrics, you are missing like 50% of the point of the whole song to begin with.

I leave the level of the kick untouched and I mix everything around the kick.Well because how I generally mix,my kicks in my older tracks were lost in the mix,so after eqing and adjusting levels,and if your kick isn't punching through,you can always turn the kick up.

Use some light saturation on your kick just to bring that transient down to the rest of your track, that will be really hard to master if it's that far above the rest of your track. Whenever I use a transient shaper, I'll throw a saturator on my effects chain straight after a few db of gain so that it sounds transparent. It just keeps you're dynamics under control and makes mastering a whole lot easier!

Well for the first time with my latest trackI used waves transx and after all the master processing,as I move away from the speakers,the kick's low end seems to disappear.Will be trying this saturation trick.