Do tram lines and JR Ferry line in Hiroshima accept Suica cards for payment like it is used in JR trains, subways and local buses in Tokyo?
If by ferry, you are referring to the ferry that goes to Miyajima, then the same as above applies. (It's also in the table above and seems to be indicated on the website of the ferry)
So depending on where your first destination is, it might make more sense to get an ICOCA card, which would be usable in most places a Suica card can be used.
UPDATE 2018: As mentioned in a comment below, this has now changed and you can use Suica, or any compatible card on the trams in Hiroshima and the ferry. The links above are also updated accordingly. So you can now the Suica card you bought in Tokyo without any issues.
I would like to update with new info: YES, starting from March 2018, you can use Suica cards or any other compatible card (PASMO, Toica, manaca, Kitaca, etc.) where PASPY is accepted, subject to two limitations:
You may not use your card as an electronic wallet, only to pay for transportation;
you cannot charge your card using the PASPY charging machines. Go to a JR West station (or convenience store that accepts ICOCA) to do it.
Also, this is uni-directional: you can't use the PASPY where other cards are accepted. Toica in Hiroshima, yes; PASPY in Nagoya, no.
Since the Hiroshima Tram and the JR West Miyajima Ferry are forms of transportation, you can use Suica on them.
UPDATE: I just rode on one of them. According to what the notices say, the PASPY discounts do not apply to users of other cards. So you'd pay a bit more.
Source: Japanese Wikipedia
No. The local card is called Paspy, and through an agreement the Icoca card of JR West is accepted as well. However, this does not extend to other cards which are usually "compatible" with the Icoca, such as the Suica, because Paspy is not a member of the nationwide group of cards which are all mutually compatible. More information about IC cards is available on japan-guide.
This is also true of the JR Miyajima Ferry, because it is not operated by JR West, but by a separate company. Remember that "JR" is not a single company but a consortium of many different companies, with varying levels of cooperation between them.