There are couple things to consider that depend on where the conference is located and whether you have a choice in hotels (i.e. do you have stay at a certain hotel for work reasons).
Generic advice
1) When you do the Universal part of the trip, I HIGHLY recommend that you stay on property at Universal at one of the three premium hotels (Portofino, Hard Rock, and Royal Pacific) if you are going to do more than one day a Universal. While the rooms are more expensive than off-property, you get Express Pass from the day you check-in until you check-out (that will save you at least $140/day). You also get early admission, which makes getting on the two main Harry Potter rides much easier. Plus the on-property hotels are very convenient as you can walk to the parks and City Walk.
2) Morning and afternoon traffic in Orlando (particularly I-4) can be painful. If you are not near Disney, getting to the park in the morning can be a chore unless you go real early. My standard advice to people is avoid I-4 if you can.
3) For some people, Hollywood Studios and Epcot are half-day parks. You may want to consider getting the park hopper option (a $60 cost) if you fall into that category and spend half day at each park. That will also give you the flexibility to visit MK if you want to leave Animal Kingdom early.
4) I do not think spending $100 more to get a 3 day ticket and then visit for half a day is a good value. You may want to consider going to Disney Springs on the half day if you enjoy shopping (or at least browsing stores)--perhaps have your husband meet you there for dinner. Though if you enjoy shopping, you may prefer to hit the outlets in Orlando.
5) Depending on your budget (both time and money) and your sweet-tooth factor, you may want to do one of the dessert parties.