Fusion360 cad beg...

I'm tryingto convert from Rhino to fusion 360.

The following was done in rhino, I'm trying to learn how to do the same in fusion...

I can easily draw this in fusion a Extruded cylinder with a hole in it.

I Can also draw my o-ring groove in fusion....

In Rhino I next draw two spheres.....(Blue and green)

Then I generate the line where the spheres intersect the cylinder.
(Inner intersection lines have been removed for clarity)
(I did this twice and the blue/green colors swapped  sorry for the confusion)

I then use the sweep2 command in Rhino to make a solid from o-ring profile and the two "Rails"
This is correctly tangent to the cylinder surface and has the correct o-ring breaks, radis etc...

Then subtract the solid and I have my o-ring grove.

So my fundamental fusion 360 issues....
I can't draw the spheres based on points, only dimensions. The lower dimension is easy to derive its the hole radius +the oring offset. The outer sphere is a lot harder as the oring groove sides are not straight and while I can place a point in the appropriate place fusion won't let me draw a sphere to the point. That problem I could work around with some triganometry, but the 2nd problem I can't seem to solve. I need to create a pair of lines to sweep the pattern, these lines need to be the intersection of a sphere and the cylinder. I can't seem to create this geometry no matter how I try.

Advice welcome.