The Error Uploading doesn’t have anything to do with the limit, it just means that tumblr won’t upload it. I usually find it’s because the gif is too saturated or it “doesn’t like” the colors. That’s why I usually add a gradient over gifs that do that, cause they’ll upload after you put a gradient on it like black and white. :) Hope this helps!
Check out this blog and it’ll give you different ways to size your gifs for photosets :D

This is for the anon who wanted the print screen of my gif settings. I can’t answer asks for some reason :/
To edit all the frames at once, edit on the first frame. Whatever you do to the first frame will change the other frames along with it :) And make sure your editing layers such as curves and coloring balances are at the very top of your layers so they will change all layers.
Just once :D
It doesn’t matter when you add them, it just matters where it’s located on your layers. Make sure it’s the topmost layer on the side because any editing you’ve done to your gif such as coloring or increasing brightness will make the text look blurry and unquality :)
On the side where the layers are listed, next to them is a picture of an eye. The eye means it’s visible. So go through the frames that you don’t want the text on and deselect the eye :D
You download the psd, then open it up on photoshop. Then drag the layers used to color the image of the psd onto your photoshop document. Then you can edit the settings as needed :)
Make sure that your text layer is at the very top of all the layers so that it’s not underneath your coloring. Sometimes that can distort the text and make it look all weird. Hopefully this helps!
Hmm, well mine usually move at .1 second or .12. Just play it back a few times and if it looks good, keep it :]
If you’re using Photoshop, go to the Crop tool or just press the “C” key. Then you drag the crop hair things over the parts of the image you want to keep.
When I save it? Hmm, depends on the gif really. But I try hard to at least keep it over 128, if it ends up going below that number I edit the gif more.
For mine, everything I edit on the first frame affects all the other frames. So try making your settings on the first frame. You can do that or press this little button on the right of the animation window:

And select Match Layer Across Frames, and it’ll make the layer and the settings the same on all layers. :]
Once you open your movie File > Import > Video Frames to Layers you hit the dot that says, “Selected Range Only.” That way when you find that one section of the movie you want, hold down the Shift key and press play until you’ve gotten all that you wanted to gif.