Represent the number of "multiple pending transactions" you mention as x.

Calculate the fee as:


Let's call the number of this result y.

Now do the following: (Make sure the preferences states to "Check transaction before broadcasting")

1. In the "Addresses" tab click the arrow next to "Change" to show your change addresses.
2. Find the Address in your change addresses which contains the change from your MOST RECENT UNCONFIRMED TRANSACTION. (Find this by right clicking the transaction and checking the details window and look at the addresses and amounts of BTC at the bottom window to find your change address)
3. Right click the change address in your "Addresses" tab, and click "Send From." This will take you to the send tab.
4. Set the Fee box to y that we calculated. The unit is BTC.
5. Send the remainder of the bitcoins in that address to another address of yours.
6. Click Button to sign and check transaction. (There should be no error, as it is not being sent)
7. On the check transaction window, Click save. Then save the file somewhere.
8. Open the file, and find the looooong string of hex characters between quotes.
9. Copy the string (like 01000000bef39df829...00000000)
10. Paste it into http://eligius.st/~wizkid057/newstats/pushtxn.php but wait on clicking the button.
11. Click "Broadcast" on the Electrum transaction checking window.
12. Wait about 20 seconds. (or if an error message pops up in Electrum, just go straight to the next step)
13. Click "OK" on the website to push the transaction.

If the website gives an error like "already in mempool" or something like that, then your transaction propagated fine... but if not, then you'll probably have to wait until Eligius mines a block.

This will confirm all your transactions at once.