You can sell them to players but there is no shop in runescape that sells or buys tiras.
You have to smuggle it out in a crate of bananas. Fill a crate with bananas for Louis, but before talking to him, slip the bottle of rum into the crate. Then have him send it to the mainland; you can find the rum in the back of Wydin's shop in Port Sarim.
Yes, the only talisman shop that sells them is located in the runecrafting guild. Although they do not sell blood. You buy them with guild tokens obtained from the mini-game there.
you can buy eye of newts from the mage shop for 3gp in port sarim and sell them in the grand exchange for around 70gp :)
I don't think there is any such thing as a player-owned shop in RuneScape.
a shop
The shop is at Port Sarim.
Merching means that you buy something reall cheap and sell it for more. example: The clothes shop lady buy 10 pink sirts from her for 20gp and sell at G.e. for 1k.
Jagex shop since their the creators of RuneScape.
tutoiral or a ax shop
the genral shop
Briefly, you can get some resource and then sell it on the Grand Exchange. For example, you can do mining, woodcutting and fishing, or kill monsters, and sell whatever you get. Search online for something like "Runescape money-making guide", for more ideas. A fast way to do this is to get a bronze hatchet from the axe shop in Lumbridge, then chop down the trees near the Grand Exchange and sell them there.