Hull "toe-in" and hull vs hull "vertical flexing" Questions

I'm not exactly sure how to ask this, but here it goes.

When looking at a used boat to purchase is there a way to test for hull "toe in", ie side to side movement?

Also for vertical movement of one hull with relation to the other? In other words, you held one hull in place and "lifted" the other using very little force and this hull moved significantly while the other held in place. What is a good way to test for this? Also how much movement would be considered "normal" / "allowable"

Thanks in advance for any tips.

I always just strap the boat down to a trailer by going over the tramp and down to the cross bars so that the hulls themselves aren't totally secured, then start pulling/pushing different directions and seeing how the other hull reacts. If the castings are worn out this will be obvious pretty quickly.

Hope this helps,
Dustin