Yes you can use the outward leg of any flight for the distance Silver Badge (multiple Soaring Performances can be claimed per flight).

From the FAI Sporting Code Section 3 Gliding 2.2.1.a (Silver Distance) – “A straight distance flight from a start at release to a finish fix located at least 50 km from release and at least 50 km from the fix recorded at the beginning of the take-off roll”

So to attempt to answer your questions.
Firstly, the silver distance doesn’t require a declaration so you don’t have to designate anything before the flight (although the broader context of your question was about an Out & Return flight so perhaps you’re declaring that).
For the actual application I would suggest entering in the “If START & FINISH points are selected post-flight” section
Start Point : Either your release point or the beginning of your take off roll, whichever is the closest to your Finish point.
Finish Point : Select a location that is at least 50 kms from your Start Point. This will be a “Fix” contained in your IGC file that records that you flew to this location. SeeYou will probably be easiest to find a fix as it displays your IGC file graphically.

Some other considerations
1. Loss of Height limits (SC3 2.4.4). As the silver distance can be less than 100 kilometers the 1% rule needs to be paid attention to. So don’t pick a finish point that would attract a Loss of Height penalty if there is another point (also > 50km from the start point) that doesn’t have a LoH issue.
2. (SC3 2.2.1.a) “The Silver distance should be flown without guidance from another pilot”, so don’t team fly with another pilot or seek any advice over the radio.

Hope this helps
Kelvyn

If the answer is YES, the next question is about filling out the form. Do pick a point along the outward leg from the flight record and use that to designate the “Landing Site” on the Award Application? Or do I need to designate a landing site before the flight and declare that as the landing site and then fly over that point? Like a turn point in a task?

I looked for answers in the forum and could not find any relevant comments.

Thanks

An important piece of information is missing from the display charts which I suggest would assist many in planning their flights to accomplish their goals each year.

That piece of information is:
1. For speed records – include the record speed display in KNOTS (along with mph)
2. For distance records – include the record distance display in Nautical Miles (along with statute miles)

I bet I’m not the only one that does this conversion, whether on paper, phone app, PC app, or brain power app.

Thanks for your consideration,
Stephen Michalik 416800