Re: Slight Ukemi problem
First Jujinage. If Nage throws you with the top hand at his shoulder height, keeps hold of this hand and lets go of your other hand as he/she projects you are supported and can also slap. This makes the Ukemi much easier and safer.
Second Kotegaeshi. I assume you mean the high fall. Students initially learn to take a backward Ukemi. Often when they make the transition to a high fall they still start to bend a leg. This means that they have to project themselves higher than would be necessary if they had stayed upright. Could this be your problem
Hope this helps,