Hi @Dark239.
First, lets say it up front - Meraki may not be the right solution for you.
Typically people who use Meraki VPN technology use it for site to site connectivity for their own sites, and as a result use AutoVPN. AutoVPN takes care of the keying and the rotating of those keys.
I only put Meraki forward to my customers when the need to build a VPN to a non-Meraki device is simple (or not needed at all). If their are lots of branches and complex VPN needs then I go for both Meraki and a Cisco router. Something like a Cisco 891F is around $USD600. Cisco routers have (by far) the most powerful site to site VPN capabilities. If the customer has medium complexity site to site VPN and medium complexity user to site VPN needs then I would use an ASA, as the AnyConnect remote access is by far the most powerful remote access solution.
Yes, I would also like IKEv2 support. I don't see any point in the industry continuing to use IKEv1.
I'm confused about your monitoring comments. User moniting in MX is substantially superior than an ASA or Firepower. Make sure you have detailed traffic anaylsyis turned on under "Network-Wide/General".