Actually, /pe-cy is fine now. I don't like either /en-cy, especially the second one. It interferes with by brain's language detection. The first one is too skeletal and jumps out of the line because of that. I think it will be fine if /pe-cy and /en-cy have dissimilar widths and the original /en-cy is used.
I think we can all agree that the serifed /р is at least as old as the rounded /р, so rounding it won't make your font look more authentic. I would compare it to squeezing the umlauts into the bounding box of /A /O /U in a font you want to make more German. Yes, it's something German typographers did, yes, it's something that will make that German influence obvious in your font, no, it will not make a German designer choose your font over another unless they are actually in need of a font that does exactly that.
Italics: The bowl of /che-cy is too deep. /de-cy is again surprisingly good, but its perceived slant is somewhat different from the rest of the letters. It's a pain to get right, but it needs to lean a bit more to the right. Usually a small adjustment of the tail is enough. /she-cy and friends look good in medium and bold weights, but the final upswish of the pen looks forces and anemic in thin weights. /softsign-cy looks like /hardsign-cy in bolder weights. The initial stroke grows too much when emboldened. /yeru-cy has this gap again. Tighten it up just a little bit.