While there are threads...there really should be a "where do I start" page with some options of how to go about it and what tools are available and how they work. All of the information is here...you just kind of have to search it out and learn. Bottom line.
You aren't just migrating easily to HE from ST without work.
There are tools to replicate devices from one hub to the other so you can have "virtual" devices going in either direction to allow you have both hubs running at the same time. This allows you time to migrate devices from one zwave/zigbee/cloud/local to the other hub slowly. Yes it takes some replicating and duplicate work.
Yes webcore can be run on hubitat. There are threads on that. Rule manage is Hubitat's way of complex rules. There are apps just like ST for simple lighting automations/etc. You'll find those in the apps area.
There is no easy way to do things like "Routines" (at least that I'm aware of someone might correct that) to simplify setting up those "I'm home" "Goodbye" and "Goodnight" routines. You'll be building those yourself.
Some suggestions.
- Look up your devices BEFORE you port them over on here to see if they are compatible and what issues you may have with those. Do those last.
- Have a plan. Everyone does this different. 1 room at a time, etc. but have a plan.
- I found it helpful to export a list of my devices from ST and put some extra columns with Zwave/zwave+/zigbee/AcORbatt/etc. Then I kind of knew what I was going to migrate based on location and repeaters.
- the z-stick while not required to exclude was VERY handy for me as other suggested. It allows a bit easier exclude of zwave devices with a simple push of the button. You do not NEED it. I would exclude from the HE hub...then turn around and include it if you are not using the z-stick.
I read and played for a few hours and then just barged and moved 90% of my stuff in 24 hours. Not sure I would do that a 2nd time. I think I'd migrate just a single room that had examples of every type of sensor (motion/light/dimmer/contact) and really play with RM with JUST that one set of devices to figure out what you can do. I have about 30 rules and afterwards went back and found better ways. I could have avoided this had I played for a few days or a week.
To replicate devices from ST to HE: Hubitat™ SmartThings Integration - this is one way. ST to HE that's it.
To replicate devices from HE to ST: [RELEASE] Other Hub SmartThings Integration 2.0 two way communication. ST can control HE devices with this.
Excluding devices from ST: Inclusion, Exclusion, and Factory Reset procedures
General reading: Hubitat Documentation
Hope this helped at least a little.