I learned from my searches result that Iris V2 outlet is both a zigbee and zwave repeater however Iris product is no longer selling unless you buy it from Ebay etc.
Is there a newer zigbee and zwave combo repeater?
I check Aeon and they seem to only make zwave repeater.
Second question, does zwave repeater must be specifically use for zwave plus or older zwave repeater will work on plus too?
Nope.
A Z-wave repeater is a z-wave repeater. Both will repeat messages for the other. However, your mesh will operate at the slowest speed of your devices, so if you have regular z-wave, that will be the speed limiting factor. Also, older z-wave devices don't all support "beaming", which is a form of repeating that is required by most new-model z-wave locks. So, if you're going to have a large Z-wave network, I wouldn't scrimp. However, if you plan on investing heavily in Z-wave plus switches/dimmers, they all act as repeaters. So, you may not need strictly a repeater device. Depends on what you device plans are.
I think I probably will need a zigbee repeater for the lock in basement which is a zigbee. The lock frontdoor upstair is a zwave plus and I have not yet had any issue so I am good there but I thought it would be good idea to get a combo a zigbee and zwave repeater if I was going to get a repeater for the zigbee.
I plan to go all zwave plus only for light switches/dimmer. I am not going to have any non-plus on my network but there will be some devices that i probably will have to go with zigbee since none is available in zwave plus only.
There is one I am looking at and thinking to buy is the Hampson Bay fan controller which is a zigbee unit and it seems that more more products are coming out in zigbee version so it can support on Alexa / Homekit / Google units etc.
Like what? I can't think of any device that is available only in Zigbee. There are some that are only available in Z-wave, for example doorbells and sirens. Zigbee is more popular for bulbs but there are a couple z-wave bulbs out there. But your Zigbee bulbs should be on a separate zigbee network from your sensors/locks anyway.
Like a ceiling fan controller with.a remote control .. even I know I can control the fan using dashboard etc but I would like to be able to control it with a remote control from the table drawer next to my reading chair so i don't need to get up to walk to the dashboard on wall to adjust the settings.
So far only fan controller that I found which come with a remote controller is the Hampson Bay model and it a zigbee .. all the zwave fan controller seem to come out without a remote control and not a zwave plus .. I am still searching for one ..
And while i was checking out devices to buy, there seem to be a whole lot more wifi home automation devices than there is zwave plus or zigbee.
With Hubitat you can use any button controller as a fan remote. Why would you have to use an RF remote?
One doesn’t have to use the RF remote that comes with the Hampton Bay zigbee fan controller. For fans with a light kit but only one load wire at the switch box (and no neutral wires), the Hampton bay module is a great option to provide independent control of fan and light.
AFAIK there is no z-wave equivalent of this device.
Edit: just to clarify for OP. The Hampton bay zigbee fan module has two methods of control.
The RF remote that comes with it transmits a signal in the 300 or 400 MHz range, it’s local-only, and many other fans work with a remote like this.
But it also has a zigbee module that enables control by a zigbee coordinator like Hubitat. That makes it pretty unique. So it’s true that any button controller that pairs to hubitat can be used to control the Hampton bay fan module. I use Lutron picos’s for example.
I am aware that anything be used as a button for fan and I plan to set up some zwave switches which 1 taps control the room lighting and more than 1 taps control the fan and light on it.
All of our fans in the house are direct wired and the chains on it is only way to control it. It is not connected to any of the wall switches and we have 4 young children that it would be easier for them to use a simple fan remote control to control it. (none of them can't reach the chain yet)
They all love peanut butter btw .... and ... we would like to keep peanut butter off of our dashboard 
And lastly, I am a strong believer in combining old and new tech together so if HE goes down for any reason then we still can control all of our devices until we fix it or get a replacement if needed.
This is one main reason why all of our three exterior doors, which have electronic lock, still have a keyhole on it :).
We will never install those keyless lock on any of our door but we don't carry house key on us anymore however we have it hidden outside somewhere.
I did noticed that there are pretty much no zwave fan controller that comes with a remote however what about those wifi fan controller?
Do you know if HE can control any of those wifi fan controller on the market that come with a remote?
Something like this?
https://www.amazon.com/Ceiling-Controller-Compatible-Required-Universal/dp/B07Z948VY4/ref=sr_1_13?keywords=zwave+fan+control&qid=1584366948&sr=8-13
or
This is a very good reason to have the option to use the RF remote that comes with it. I have the remotes in a drawer for my two living room fans; if hubitat fails for some reason, I can still control the fans. I don’t routinely use the remotes, as this can cause the fan and/or light status to be out of sync from hubitat’s perspective. But in a pinch, they can be useful to have around.
They would probably need some kind of specific, custom driver, if they could be integrated at all. Sorry I’m not a developer/coder so I can’t really comment on how likely/possible that is.
In general, my personal preference is to avoid WiFi-based IoT devices. They are usually more difficult to integrate with Hubitat (and other hubs too), and they use up an IP address on your LAN. There was a device by sonoff that’s been discussed in prior threads, but iirc it wasn’t clear whether it was certified by an independent testing lab like UL or CSA. For a device that connects to mains wiring, IMHO that’s a deal-breaker, regardless of how competitively priced the item is.
Download the Hubitat app
