I know I can just enter the amount to be sent in the Amount field on the Send tab but when doing this I do not know which inputs will be selected and I do not want Electrum to take inputs from different accounts.
it sends from the selected account.
Not sure I understand what you mean Thomas, how do one select a specific account in the 'Send' tab?
Only way to do this, that I'm aware of, is to go to the 'Address' tab and then to select all the addresses you want to use for the input side and then to select 'Send From'.
What I would like to see is to be able to right-click on the account label/name and then select 'Send From' and then knowing that only addresses within that account will be used for the transaction. When doing this Electrum should only include addresses inside that specific account. If there is not enough funds on those addresses then it should give a warning that the account does not contain enough funds and maybe with an option to add more accounts i.e. 'Selected account balance insufficient for this transaction. Would you like Electrum to add more accounts to satisfy this transaction.... Yes/No'
In that way you ensure that transactions never gets mixed up between accounts. I do not want to do a business transaction on my 'Business' account and then have Electrum include an address that's actually under my 'Personal' account.
EDIT: Think I should just clarify. I use Electrum together with a Trezor. So on my Electrum wallet I have 6 accounts. So when you go to the 'Address' tab you will see Main Account, Account 1, Account 2 etc... and each account have their set of addresses inside the account.
My Main Account is for business transactions. Account 1 is a personal account etc.. So when I send funds I want to be able to limit it to a specific account. Only way to do that is by going to that account and selecting the relevant addresses and select 'Send From'. There is no option to for example right-click on say Main Account and select 'Send From'.
When entering an amount in the 'Send' tab Electrum selects whatever inputs are required for the transaction, whether they come from just the Main Account or from the Main and other accounts, just as long as it satisfy the needs for the transaction. This means that I might do a business transaction yet end up with inputs selected from my business and personal accounts which sort of messes things up.