Is it theoretically possible that Ledger has a backdoor for the devs?
Most of Ledger's source code is open-source. Nobody can tell you for sure what the safe element does since the code is not public. But I figure that if such a backdoor exists, they had a lot of opportunities to abuse it in the past, and they didn't.
In theory, everything is possible. Trezor is completely open-source but can you personally check the code and inspect what it does? Is it theoretically possible that Trezor's source code is also in some way backdoored or bugged but nobody knows how to find the vulnerability parts? Or those that do aren't telling us. There is that small possibility too. It all depends on you and your paranoia level.
As far as I remember, they mentioned the reason a backdoor wouldn't be worth it somewhere on Reddit, they basically said they'd have so much to lose by creating these backdoors when they could simply develop something successful and create a large company out of it - which is what they basically did. I'm a little paranoid when it comes to the closed-source manner of the safe element too, but if they ever put some backdoor inside our Ledgers and want to ever scam us all, the damage will be way beyond my loss of funds - it'd probably basically parabolically strike BTC's price within minutes.
Edit:
DdmrDdmr quoted their reply
I trust my iPhone more than my mac. Because I aint have a jailbreak and aint use any crazy apps. Just the basic stuff. Risk is always there. But on the Mac I installed some apps that I downloaded from the internet and not from the app store. I will try Coinomi. But it looks like its not a easy task for a noob and needs lots of reading. If my BTC is safe, I could accept losing the forks in worst case scenario, thats ok. First I wait for the Ledger and then I do the fork stuff.
I understand. The last time I used Coinomi, sweeping a paper wallet was as simple as installing it, choosing "Sweep Paper Wallet" (or "Sweep Wallet", can't remember) from the top-right side of the screen where you have the menu, scanning the private key (or manually inputting it) on the window that pops up and that's basically it. Coinomi would then just scan my balance and do the transfer in case I confirmed the transfer.
Here is apparently a tutorial on their website for sweeping wallets:
https://coinomi.freshdesk.com/support/solutions/articles/29000009716-migrating-from-other-wallets-into-coinomi, but it doesn't let me access the link from Tor to confirm whether the article is still there. Please check it out and see if it helps.
As far as I know though, Coinomi
used to be open-source but it's not anymore.
The keypoint is not rushing the process. Make sure you write down the proper Coinomi and Ledger seeds on a sheet of paper and come back here if you have any question.