Hi there - haven't done these bosses via boxing yet so I will just tell you what I learned about Maexxna with my other characters.
- tbh shamans aren't the best healers in this place - make sure that you have all possible hots (I think they only have one?) on the tank before she stuns (i.e. puts them into a cocoon) all of them. Use 1 of your your short cooldowns (f.e. trinkets) on your tank.
- At about 30% Maexxna automatically enrages, use all remaining cooldowns on the tank character, bloodlust would be very useful and try to burn her down as quick as possible. Unfortunately with the amount of healing required... You probably will have to twoheal it somehow in order to get anywhere.

And yes, she still calls the small adds and webs people after the enrage, thats why with lesser geared raids you wait until her last webbing before burning her down (also called a damage stop ).

My two cents.