Hi Trish..
 
Though someone else may have a better answer, I'll tell you how I handle this situation.
 
First of all, CHANGING the title or keywords is done because the card has not been selling...right?  I mean if you have a card that is selling, then why change what works...so with that in mind
 
When I wish to ADD keywords, I usually add them to the end of run rather than the beginning.  
 
Does it change the order in the search engines? I'm really not sure, but again unless you have to change because of new guidelines, then the only other reason to change these areas is if it isn't being found by search engines as is, so if you can improve the card's search-ability, isn't that worth it in the long run?
 
Hopefully others will have better answers for you!