Aeris is seen at the beginning of Final Fantasy VII praying. Did she walk the path of the game with full knowledge that she would die in the end?
The way I interpreted it, is that she did know. In order to defeat Sephiroth, she would have to control the Lifestream herself, and the only way to do that, was die and become part of it. Hence, the final shot of the game is Aeris, implying that she knew was she was doing all along.
I don't thinks so
Everyone thought Sephiroth and JENOVA was dead (JENOVA's headless body was preserved for the cells, Barret questions if she is alive when Cloud see her) and only Professor Gast theorized that North Cave would only be healed by the planet after all trances of JENOVA was removed from the planet
I don't remember Ifalna every saying to Aerith about her demise if she went to the Promised Land however the Forgotten City where she died is not the Promised Land, it's belived North Cave is as it fit's Shinra's Description of a land rich with Mako which North Cave is a festering wound on the planet which lead deep into the Lifestream which Mako comes from
Aerith could probably hear the Planet being in pain, being an Ancient herself and i think Tsung questions her about her hearing voices from no where being a sigh of one, she refuses becauss she knows if she said yes it would just confirm to him who she was and be taken away.
her praying for the planet that it can keep on living and for it's safety, or she could just be comuning with the planet in general which is why she stops and thinks for a moment when she goes to get up.
there's also a theory she was praying to Holy to continue keeping the planet alive, which goes along with the theory that the reason why Holy didn't start right away at the end was because Midgar's Mako Reactors where still running, it was only until the last one shut down from damage from Meteor did Holy start up