Sarah, in principle all G scale points are connected through, and don't rely solely on the face of the point blade touching the stock rail.
Having said that, some of the in-built connections are sometimes 'iffy' and cleaning all of the gunge off is never a bad idea - with electrical connectivity, sometimes every little helps.
From what I can picture of your layout, with two parallel tracks and four turnouts, you can put the power feeds anywhere (you wouldn't necessarily be able to do it in the smaller scales, but G scale points do not isolate any rails).
However, there is nothing to stop you adding another pair of feeds. It is possible to experience some voltage drop through the points, so you could add a second feed to the other parallel track - you won't need isolation.