Where can I see INSIDE Electrum when I sent initially the transaction to the mempool?
You can't, because this is non-recoverable information and Electrum simply doesn't keep track of this information to my knowledge.
2.) The blocktime is a timestamp without a reference time zone and therefore useless.
Its like if I say "I pay you 4000". Pay what? US-Dollar, Euro, Swiss Francs, British Pounds?
You're wrong as the blocktime is "recorded" in UTC and this is perfectly fine because any wallet could display it then converted to any local timezone if that is what is wanted.
Your comparison is flawed. When the timestamps are in UTC, that's unambiguous enough. And additionally it's not needed to disclose the local timezone of a Bitcoin user.