That is an area where Moho is clearly weak right now. Implementing this proposal would be amazing:
viewtopic.php?p=200052&hilit=nudge+keys#p200052
While we wait for improvements, a lot of users use scripts that help with timeline management. The most used scripts are:
A. Evseeva's Key Tool script:
https://mohoscripts.com/script/ae_keytools
This tool does a lot of cool things with keyframes on the timeline. It works with the layer you have selected and all its children. You can use the top-right three last buttons V, v and X to show all animated layers on the timeline, show only those that are animated more than the first frame (to avoid showing layers that only have that keyframe to hold initial positions), and stop showing extra layers on the timeline. If you have a lot of animated layers, use Moho's consolidate layer channels option on the animation menu. I have a shortcut for it for this reason, and another to quickly undock the timeline to make it almost full screen. I love it when I need it. With those three things you are the master of the timeline.
The script also have some arrow buttons to shift all keys for you even if they are not showing on the timeline. And also some copy-paste buttons that I like more than the deep frames, because you have more options and you can copy the state of a layer even if that layer doesn't contain any animation, something that deep frames don't do and it's useful to copy the 0 frame of a layer to a duplicate that you want to update when there is no animation for example. And a few of other buttons but I still don't understand all of them since I haven't seen any explanations about it.
Rudiger's Nudge Keys Tool:
http://www.lostmarble.com/forum/viewtop ... &start=195
This tool was created by Rudiger but it is still working thanks to Lukas' contributions and aditions to it (that's why I linked the last page of that post).
It was meant more specifically for shifting keys, and has a lot of options. I have it installed but so far I have been doing fine with just what I told you about the Key Tool script so I haven't taken the time to learn about this one yet.