Is it just as simple as downloading and it will work as normal and all coins will show in the app?
Yes, it is pretty much just as simple as downloading and it will work as normal... unfortunately, No... not all "ledger supported" coins will show in the app.
The Ledger Live app only supports the coins as shown here:
https://www.ledger.com/pages/supported-crypto-assets (23 as of version 1.6.0)
The other coins can still be accessed via MEW, MCW or their own individual apps like IOTA and ADA etc. as you are currently using them now.
The reason i am asking is that i have coins Like ADA, IOTA etc that are still accessed using their individual apps/programs (they are still signed/accessed with my wallet/Ledger)
Do i just install it and all will be good? Will they all just appear ?? Or will it ONLY show the amount of coins that Ledger Nano is capable of storing?
The Ledger Live app will let you configure which (Live supported) coins you want to display in the app... and is NOT related to which coin apps you have loaded on the Ledger device itself...
Except for the initial configuration of each coin "account" within the app... you have to have the coin app on the Ledger device to be able to create the account for that specific coin within Ledger Live:
However, after you have set a coin account up, it doesn't even matter if your Ledger device is even connected to the PC, you will be able to see all the (Live supported) coin accounts, balances and transactions for the accounts that you have already created.
I am weary of doing so as i hold a fair amount of BTC/BCH/XRP etc
What would you do as it is a PAIN uninstalling/installing coins it supports all the time.
Will the Ledger Live Manager negate this??
On insofar that you won't have to uninstall/install coin apps on the device to SEE your (Live supported) coin accounts that have already been created... but you'll still need to have the coin apps installed on the Ledger device to:
- Create an "account" in Ledger Live App for that specific coin
or
- Send Transactions for that specific coin
TL;DR:Essentially, Ledger Live acts as a "watching-only" wallet... and it only needs the coin app installed during setup so it can properly generate the correct "xpub(s)" for that coin so it can create the right account(s) etc. Once setup with the xpub(s) imported, Ledger Live will open and only show what you have explicitly setup to show... regardless of coin apps installed on the device or if the device is even connected.