Mine leans away a bit - it's just something you get used to, and is a consequence of the 'modern' placing of the strap button to avoid neck dive. I'm surprised you would get any neck dive as that mainly affects older basses that don't have the button on the neck heel. You'll just have to learn to play without looking at the fretboard
Don't hang the bass too low. I did that the other day with my new extra-long Comfort Strapp (recommended!). It felt great when playing, but I had a touch of tendonitis for a couple of hours afterwards. I'll hitch it back up a notch for my next gig
I'd also recommend lock straps, although you'll probably have fun with the thin, short screws that come with Schallers. It's a 2 minute job to glue a matchstick into the old holes, which then give you something decent to screw into. Solid