Thanks for your questions, Dizdi! Here are the answers...
1)One of my Zimbies is adjacent to 1 orange player's Zimby and 1 yellow player's Zimby. Is it possible to move my Zimby away from them in my turn or is it locked?
You are free to move your zimby as you desire (provided there are adjacent empty tiles or your zimby joins an adjacent zimby column). Combat lock for your zimby only happens after your zimby attacks a creature and fails to kill that creature, or is attacked by a creature that fails to kill it.
2) If I attack the orange Zimby I cannot move until I kill it,right? Because I am combat locked with it. If the orange Zimby is dead do I have to also kill the yellow one?
Part one is correct: you must remain combat locked with the orange zimby until either you or the orange zimby dies. Moreover, combat lock also requires your zimby to attack the orange zimby on your turn and for the orange zimby to attack your zimby on its turn every round until the combat ends. (Note: combat ends/combat lock is automatically broken if one of two combatants is moved out of the combat zone of the other -- for instance, by a Smell o' Meat witchery.) As for part two of your question: as long as the yellow zimby does not attack your zimby, and as long as your zimby doesn't attack the yellow zimby, you and the yellow zimby are not combat locked, so you do not have to attack it upon defeating the orange zimby... unless you want to.
3) 2 of my Zimbies are in a column with 2 of the yellow player's Zimbies. If I spend 1 mojo to move can I separate them from the column, move both of them 4 spaces or move them together for 2 spaces and then move 1 of them the remaining 2 spaces?
No. Movement is spent to move an entire creature only and may not be subdivided into component creatures. So, if you move both of your zimbies out of the multi-tribe column, you are moving 1 creature -- a column of two of your zimbies. You may move that single creature out of the multi-tribe column as you wish with your 1 mojo: 1, 2, 3, or 4 tiles away. If you want to move a single zimby out of your new two-zimby column, you must pay additional mojo to move that creature -- a single zimby column.
4)When Zimbies separate themselves from a column, do they have to stop moving?
No, they may move as far as the mojo will take them. However, they must end all movement when they pick up an item or join a column, even if that column is comprised only of their own tribe.
I hope these answers help! Please let me know if I can provide more clarity.