It's probably very safe to say that the GF 7nm process is not as good as Intel's 10nm, and I will put my life on the fact that we will not be seeing an 8+core Ryzen2 running air cooled at 5GHz anytime soon. For the next few years IPC is king for AMD, as Intel will match them on core count soon, and probably still better them on clock speeds.
GloFos' 7nm, from the specifications I have read, is in fact about as good as Intel's 10nm. That being said, Intel is said to start with 10nm+ , which is most likely better (but still much closer to GloFo's 7nm than what Intel's 14nm+ was to GloFo's 14nm, when Ryzen launched in 2017). Whether GloFo's 7nm is as good as Intel's 10nm is irrelevant; you need to compare it GloFo's 12nm or 14nm process, which the last two Ryzen processors were one. Do you honestly believe their 7nm will provide less than 10% possible frequency increase over their 12nm process?
The upcoming 7LP 7nm FinFET process will, according to GloFo, provide the possibility to achieve around 30% performance improvement over 14nm, or 20-30% over the current 12nm process of the Ryzen 2 (which I believe was a quick and dirty transition from AMD, as they have the majority of their focus on Ryzen 3 / Zen 2). Traditionally, the actual clock speed improvements are half of those stated to be possible (because of various factors, like architecture limits), so my I guess is at least a 10% frequency improvement here -- around 4.8 GHz turbo on some cores, and all cores at somewhere around 4.3 GHz is very, very plausible.
For the next few years IPC is king for AMD, as Intel will match them on core count soon, and probably still better them on clock speeds. So AMD does need to aim and reach higher than the current Intel architecture, a
This is true, and AMD will already at least match Intel in IPC with Ryzen 3 next year; that fact is pretty sure. But it's certainly not the 15% IPC you claim....
How much more improvement they will do in IPC further down the road remains to be seen, although I doubt it'll be as good as Zen 2. There's supposedly going to be two major revisions to the architecture, with Zen 2 next year being the first one. The second one is Zen 5 (Zen 4 name is being skipped) in 2021. AMD are said to have a whole new architecture ready after that as well, from what I've heard.
In the question of clock speed, I think AMD have a greater base from which to start from than Intel. Frequency increases have their limits, and Intel can increase the frequency only so much, before they need to stop. AMD, on the other hand, still have pretty conservative clockspeeds in comparison, and have greater potential of performance increases as we move along. A potential AMD needs to take advantage of: single-digit IPC superiority is not enough to make up for their clock speed deficit, if they want to perform better than Intel Core.