In a standard shmoneh esrei, we have a middle section of bakashot. Because we do not make bakashot on Shabbat (as evidenced in this question), the middle 13 brachot are omitted. However, the final section of 3 brachot (avodah, hoda'ah and shalom) remains. This leads to two questions (sorry if they should be split but I think they might be related):
Isn't the Avodah bracha a bakasha? If I recall correctly, the gemara in the 2nd perek of Megilla (18a, 5th line) shows the logical conection between the brachot and explains that only after hashem receives our prayers will we have the avodah, so if we don't say the bracha of shma koleinu, how does a request for the avodah make sense?
Why is it written in 3rd person, referring to the Ishei Yisrael and tefillatam, instead of, for example, tefillateinu.
a- For Ratzei I saw an answer in "Nativ Ha-Bina". Originally Ratzei was a 'thank you' Bracha. We said thank you that Ha'shem is willing to except our sacrifices but since our temple was destroyed we changed the bracha to a request.
b- I also had a question on Ose Shalom, I mean also that should be a thank you and not a request bracha (3 last brachos are thank you brachos)!?
I got an answer (from a Rabbi) that asking for help by its self is giving grace to our father. So when we finish the prayer the best type of thank you is to ask for help and in this way to remember our position as the "Mekabel"