Option 1 - I thought that it is a general rule that ships must not touch each other until I played today. Even if it is allowed to place ships touching another one it is not recommended as a strategy. If nothing is changed here which would be ok in my opinion it would be very important to have a BGA rule page for the game, not simply a wikipedia link. The English, French and German pages I just checked differ in many aspects; while in the English and French page nothing is written about this forbidden placement, the German has the rule. (But note that even in the example given on the English and French page no ship touches each other.)
This is a general problem with such common public domain games that there are so many house rules and variants. There should a rule page on BGA which explains the game.
There are some more interesting variants taken from the German wikipedia page, e.g.
* You take a row of x shots with x being the length of your longest ship still alive.
* You place 3 sea mines (1 square). If the enemy hits such a mine his ship gets destroyed (which means that you have to announce which ship takes a shot before, which might become annoying in an online adaption). If I understand that correctly you will always take 5 shots until your carrier is lost, even if you announce to shoot with a shorter ship (see below). It is not clear if you have to announce a ship before every shot or just 1 time before you take a row of shots (see below, too).
* You also place a fortress. This has 3 squares and must be placed at the border. It can also be in a corner (the 3 fields need not to be in a row, but every field must be adjacent to the border). The fortress has only 1 shot but sinks a ship directly.
If a ship sinks after being shot by fortress or hitting a mine you only announce that but do not give the exact position.
My personal variant would be that you tell which of your ships shoots once before taking a row of shots and then you take as many shots as the ship has in lenght.