just had to mess with it
Oh dear...lol. On the lifter... Try setting up the dial indicator on the edge of the lifter body instead of the plunger.. All hydraulic lifters will bleed down and it's no big deal and usually a function of loose lifter bores rather than an issue with a lifter.
On the ring deal... You can't re-use a ring especially on a new piston as the parts wear together very quickly and very intimately. And, you can't simply stick a new ring on the worn bore. If there is NO RIDGE.. not a small one, but NOTHING there to catch you finger nail... Then you can simply rough up the surface and stick a new ring in it. I like to use green scotchbrite over the stones of my flex hone for this... using WD40 as a cutting lube. If there is any ridge at all, I would consider the removal of the engine and bore/honing of all the bores by a shop. The alternative is a fresh new piston with a fresh new ring that has sharp corners, and a ridge that has rounded(worn) corners coming together. There are only a few ways for that to turn out... Broken ring, loss of ring seal at TDC, or broken piston. The best scenario is the loss of sealing...