leader length/weight for walleye and lake trout?

Hey, gonna get a couple of days at my cottage and was thinking it would be a good idea to do some spinning with spoons/plugs/crankbaits and maybe some jigging, targeting walleye and lake trout.. before the water gets too warm and they go deep..

anyway both my rods are loaded with 20 and 30lb braid, so I know I need a leader, I was thinking 12 lb fluoro and tying on about 2 or 3 feet with a blood knot (don't like having a swivel, i haven't had huge problems with line twist in the past)

this is just my winging it, I should add that once I get frustrated with spinning I will definitely throw on a minnow/worm on a drop shot rig, 

am i going too long/heavy with the leader or should I be good? this is my main concern

That length and weight should be fine.

i've always used a 6" wire leader with swivel at one end and a snapo at the other, those toothy critters can be rough on bare line

the lake is super clear, pretty much as clear as it gets, i'm scared to spook the fish by either using a leader or even just trying the braid straight on

I think you should be all right with a 2 to 3 ft leader.

depending on the rod I would think you would have no issues landing fish with 8lb

i run twelve pound fluoro on m y similar rigs . i like swivels, but i use a double uni knot for mono to braid connections

thanks for all the input guys, gonna go with 2 or 3 feet of 12lb (still learning my lake, get snagged fairly often), though I agree with nado, i don't need to go so heavy, but like I said, the reason being snags

Another thing I wanted to ask you guys that I've thought a lot about since I've started using braid.. It might be a topic for a whole new thread but here goes,

are leaders REALLY necessary? I find it hard to believe that while spinning, a fish in attack mode will see my braid and change it's mind right there.. I can see the use of a leader while presenting live bait  for obvious reasons, where the most natural presentations will trick even finicky fish, but I have a hard time believing it really makes a difference while spinning.

What are your thoughts? do you swear by using a fluoro leader.. and does it matter species to species?