Luremaker's websites will list dive charts. Look at lure packaging as lure characteristics are usually listed. Rapala has dive charts for all of their lures.
Another consideration is mono lb test. Heavier lb tests will be thicker and sink less. Use lighter lines to maximize depth.
Agreed, your leads are too short for these stick baits. Longer leads also = more stealth.
This type of fishing is where linecounters really shine.
When necessary, you can use small dipsys and jet divers to fish deeper. Church boards will handle this all very well.
These sites will help out. By the way there are many more out there, you just need to search.
http://www.churchtackle.com/tips.htmlhttp://www.churchtackle.com/walleye_inst.html