[Steve Bentley]

Its kind of elaborate but you could write an expression that grabs the mask vertexes of the mask that is creating the semi transparent layer and then automatically mask an adjustment layer (with a dummy mask already on board) using those coordinates. The blur would always be there on the adjustment layers and only shine through once a mask was positioned.
There are a few hoops to jump through to get access to the mask points though.

[Steve Bentley]

two things:
Give that you do have both start and end on the stroke effect – does it matter which direction the spline goes?
Just animate start and end separately. Am I missing something? Can you post the look you are going for?

before we had the set start vertex buttons we used to just add a point on the mask and it would become the new end point. Depending on where you put it, the mask would reverse directions – so you could try that.

[Steve Bentley]

Dave’s right, you will see a lot of hype about “threaded for after effects with x number of Cuda cores!!!!!!!” But these only really kick in for certain plug ins and when you are ray tracing a truly 3D scene. (Ok, 2.5 D)
But watch out too. I’ve got a new high end GTX that is fighting me tooth and nail with AE even with everyday stuff. Not sure if its a bad card or a bad pairing. Not all cards are best for AE.

[Steve Bentley]

In the layer menu under masks and shapes, select the vertex you want to be the start and hit choose “set first vertex.”
Keep in mind to that strokes of any thickness have to outlined in AE for them to come in having thickness. Otherwise they just come in a single spline.

[Steve Bentley]

I think those are less complex than you think. I’ll bet if you use the right footage of gossamer light whisps and pass it through the lense effect (moving from left to right etc) and mask the circle of the lens, and do this a bunch of times in different directions you wil get this look.

[Steve Bentley]

With a real cart and 3d model inside you’re going to have to do a whole lot of 3D tracking to nail that 3d charcter into the cart so he doesn’t drift around in there.
Keying the wires of the cart can be tricky because they reflect the enviro (assuming a chrome wire cart). So you can’t pull a luma matte off them. And green screen behind would key all the rungs – front and back so the character would look like he’s behind the cart not in it. And lining the inside with green would only let you see the front rungs.
Why not motion track empty footage and build or buy a 3d cart for your character to be in. then those two are anchored together by the animation. Take a panorama pic of the “store” or whatever so you get an environment map to reflect in the cart rungs. HDRI preferabaly if you can – the hotspots will look more real.

[Steve Bentley]

Why not just make one to reuse at the beginning of the project and then drag it from the solids folder to the time line in one move. Dragging puts it where you want it in the stack and when you want it in the time line.

[Steve Bentley]

I’m not sure what you are asking here but let me take a guess.
You can “edit or cut” layers using keyboard commands.
Unlike a NLE the footage in AE stacks, so a new bit of footage is farther down the time line and sits above other layers and it steps on the footage below.
If you put your time marker over a layer and hit cntl shift D that will split the layer at that point and put the second part above the first in the stack – so that’s like a cut.
You can just slide the elements in the timeline back and forth to line them up how you want with the top layer stepping on the lower layer when you want the new footage to take over. *holding shift will snap a layer to other layers end points)
There is no simple dissolve in AE like a NLE. You can do it but its messy. Let me know and I can walk you through it or you can look up the blend effect. Keyframing transparency can work but it’s hard to get the roll off from one to the next. But if you are just “disssolving” from a top layer to a bottom layer this can work fine – just keyframe the trani attribute of the top layer and let it fade in our fade out covering the bottom layer.
Trimming a layer is alt plus the right and left sqaure bracket keys (the trim will happen where your time marker is). You can bring the end of a clip to where you want it by hitting the sqaure bracket keys without the alt.
You can get to the begining of a clip by hitting the i key (for in) and the end by the o key (for out)
Keep in mind when you trim, you are sitting on the last frame of video not the next frame.

For a slide show of all the same length its really easy. Just bring in all the clips you want into one big stack in the time line. Make them all the same length for how long you want them to be on scren. Put them in the order you want to see them from top to bottom and then select all, the right click and choose Keyframe Assistant and choose sequence layers. Choose no overlap and bingo a staircase of shots cutting from one to the next.

[Steve Bentley]

How we usually handle this is to make the text with the effect a sub comp but make it so the effect takes much much longer than you want. Then in the outer comp use enable time remapping. You still have to insert keyframes but as long as you always alter the position of the key frame you are interested in AND the final key frame (assuming you work from left to right) the original timing between the two stays intact and you can tweak to your hearts content to get time based kerning you are looking for. And because the original layer is long you have the resolution to mess about with time. Some will argue that you can do this without having a long typing effect since AE will figure it all out before outputing the frame you are looking for – true in most cases but with the typeing effect it screws up previously revealed text just like you have found when trying to do it right on the layer.

Remember to turn on the little sun icon to keep the vector of the nesterd text layer nice and crisp if you resize things.

There’s another way too if your penmanship is good.
Use a brush and paint on a stroke over time on top of a precomped layer of text. This will record in real time and you can speed up and slow down as you see fit and then tweak the final performance. Use the painted stroke as a mask to reveal the text through. The only issue with this one is that you will see bits of the text yet to be revealed where the text line surrounds counters like a lower case e.

[Steve Bentley]

You can also stick a slider in the effects tab and link it to the attribute with the whip tool (look ma, no code to write!)
You are still using the mouse but you don’t have to enter values and you can set the resolution of the slider so when you drag it can be very very fine grained unlike the clicking and draggin on the actual attribute value.

You didn’t mention why you wanted to do things this way – that might help us help