Kyrgios yes (when he's not in the mood to double fault). Querrey maybe, will study/look up stats. Cilic no. Dimitrov hell no. Opelka is a cheat example, surely if we go down to challenger level there's a dozen bots with a better serve but a much, much worse ground game - they are no factors, people usually imply ATP level when discussing strokes.
Flatter doesn't equal flat out better, so that's moot. While de; Potro hits harder, Federer was better at hitting spots and especially hitting his FH from the backhand corner (inside-out, inside-in). Don't believe the consistency statement at all, what are your stats? Delpo does have a better running FH though - that's the weakest aspect of Federer's FH, which was pretty damn strong (*now* it's not, obviously, but why would you be comparing to now?), but he was no Sampras there, or del Potro, indeed.
Talking volleys here, so being harder to lob is irrelevant (lobs are put away with smashes, not volleys).
You seem to be talking out of your arse. Since you made your claim first, go on and do a detailed video comparison (and don't cherry-pick, do a random sample), or admit you're too lazy to bother backing your statements and 'recommendations'. I reiterate: If Ivo was really that great a volleyer, he'd barely be losing 1st serve points with that colossal serve of his, no matter who he was playing. Spamming drop volleys off those feeble returns, that's what he'd be doing.
Yeah, obviously great at volley putaways (good shot discipline), but improvisation not so much, so he'd rather stick to only going to the net in very favourable positions.