Short answer: No.
Those who are beatified and those who have been canonized have physical bodies which are (mostly) on earth (Mary, Enoch, Elijah, and Moses being exceptions). They are also in heaven in spirit. This means that they are in a very specific spot (even though heaven is quite large).
God, on the other hand, is literally everywhere (cf. Psalm 139).
I think it might be a good idea to point out that the question seems to be conflating omnipotence, omniscience, and omnipresence. Addressing omniscience and omnipresence:
Saints are not all-knowing. While the Spirit perfects the communion of the Saints, it does not make it equal to God himself. A podcast I once listened to (featuring Fr. Euteneuer) suggested that a Saint's knowledge more-or-less ends at a person's private thoughts (which are reserved to God alone). They also do not know the full mind of God (to count his thoughts we must be eternal (also Psalm 139)).
They are not omnipotent. All power which they have are received from God. I would even wager that God denies some of their requests, but I don't have any source for that. I will say that at best Saints hold similar stature as Angels. I also seem to recall that Angels are far from omnipotent.
Bonus question (if a none-catholic christian asks them to pray for them do they hear that?):
Asking for the intercession of a Saint is not limited to any group of people or restricted from any group of people. Even if someone is not baptized, a Saint may still intercede on their behalf (or perhaps especially if they are unbaptized). All persons may pray to Saints, and it is possible that any person may be answered. Of course, there is the faith element. If someone does not have faith, then it is doubtful that they will ask for intercession.