Hi,

To answer your questions:

Q1: Why not use a browser extension?
A1: Never ever no matter what I will absoultely not use such a thing. The layers of prgramming for a browser extension are so high they expose a mountain of vulnerabilities. Only full node or nothing.

Q2: Why desktop app?
A2: Because I want to get ready for a full node with 32 ETH staking, if and when this happens; and what I need to do: i don't know (yet).

Q3: Why MyCrypto desktop app and not any other?
A3: Because i couldn't find any other, and the only other one I found was MEW and they were reluctant to use the keystores approach.

Q4: Am I sure to have downloaded the right app not a phishing site?
A4: Yes i used my own method to cross-check the site, but the MyCrpto app itself has a way to confirm the key signature. It did not use that method because it is confusing as hell and required me to download even more software that could itself have its own problems. So at the moment I am relying only on the authenticity of the site.

So the only problem at the moment is:
Mist used to behave well, I open and close the app it remembers my wallet.
With MyCrypto: i have to Load the wallet each time I open the app, it does not keep the wallet open.