1-If I deploy my bitcoin node, do I have to transfer my crypto from my trezor over to my new wallet?
No.
Keep coins in your Trezor wallet as offline storage.
Running bitcoin node has nothing to do with your other coins.
2-When creating a Umbrel account, a seed phrase is generated, is that seed phrase related to my wallet, or only to Umbrel?
I am sure it's not related with your wallet, but better ask Umbrel support about that or check their documentation.
3-Does it matters if I keep my node running on a laptop vs raspberri pi? (due to raspberry prices, It seems cheaper to just buy a laptop and install Umbrel on it)
Running your node on RaspberryPi is cheaper and it spends much less electricity, but if you already have old laptop with Linux OS that will work perfectly.
I don't remember how Umbrel works exactly, so you need to check documentation for setup instreuctions.
4-Is it safe to use a third party software to connect my trezor or a ledger to my bitcoin node?
It's safe if they are open source wallets like Electrum or Sparrow wallet, but I wouldn't connect anything suspicious.
5- I noticed that Ledger allows you to connect to your own node, is that a good option instead of using a third party software to connect it?
If you can better use other open source wallet with Ledger, because their ledger live app is one of the worst craps I ever saw.