Adding speed, scale, and position effects on same clip

Hi,

I've been trying to use the speed ramp tool on a clip and also position and scale it to be where I need it to be in the frame. 
Every time I try to add scale and position keyframes in addition to the using speed ramping strange things start to happen. Is there a way to layer effects and use multiple keyframes for different attributes? 

Also, sometimes when I have multiple keyframes, if I edit one later in the timeline it doesn't change anything where I placed it but it changes things earlier in the clip...not even at a keyframe. This makes no sense to me. Then, if I 'remove attributes' sometimes my entire clip just disappears.

I'm not sure if it's all related somehow or if they're seperate issues. Any help is appreciated!

Thanks!