BlackShark

You could run this command on cmd (change the path to match yours of course): ren "C:\pathtoyourfolder\*.pkm" *.pk4

Use the dev build or wait for the next stable release.

Should be Up, Select and B.

Wait for the next stable release or use the dev build until then.

Just use PKHeX and give Double Edge to your Slaking? Alternatively PKHeX can also make the move tutor available again by unsetting the flag "Used Move Tutor in Victory Road (Double Edge)".

Wait for the next stable release or use the dev build until then.

In Gen 3? You can't, unless you make a ROM hack.

"Export SAV" is to export your save file, which is not available because you have none opened. Right above is "Save PKM" which you can use to export the Pokemon. Alternatively you could as well just drag and drop the mon out of the window, either directly from the boxes or from the image in the top left.

Tools > Data > Mystery Gift Database

Use the dev build or wait for the next release.

As it was said in the previous posts, get the dev build or wait for the next release.

Have you read the post right above yours? It's fixed on the dev build, so either use that or wait for the next stable release.

There is 3DSRNGTool that can be used to encounter Pokemon with your desired IVs. https://github.com/wwwwwwzx/3DSRNGTool/releases/latest It's not possible to distinguish an edited Pokemon from an RNG'd one.

There are no PID relations in Gen 6, you can just use any random number.

No, what I meant is to dump the ROM again by using whatever tool was used to dump it first (recommended is GodMode9 if you have a 3DS).