That is absolutely unreasonable, as the email files don’t actually tell you who the sender is beyond the domain from where it’s sent. The email protocol is SUPER unsafe and really really easy to spoof as someone from the big three
I am not happy with my provider, currently waiting for the email hosting to expire so that I can maintain just the domain there and eventually user zoho for hosting
Regarding the tools, you must take into consideration the fact that you do not have Microsoft apps on Linux (unless you run them through wine or online, which is not ideal). However there are several alternative tools, either open source (libre office-imperfect compatibility, Onlyoffice desktop-better compatibility, incomplete feature set) or closed source (either WPS office or FreeOffice). PDF is an annoying one as unless you feel comfortable with libreoffice draw or you want to do more basic editing, tools for PDF on Linux are kind of lacking
To solve number 4, I need to know the desktop environment you went with. Is it Gnome? If so, there’s a tweak (a Gnome extension) that makes the taskbar stay on screen permanently or appear when you hover over it (kinda like MacOS) and then you just right click a program you’re using in there to pin it to the taskbar