1) The Carnival Paradise is the only 3-4 night cruise to Baja / Ensenada. However, HAL goes to the Sea of Cortez, but that is a ten night cruise.
The Paradise has miniature golf and a water slide.
2) You can book Early Saver, which has a non-refundable deposit. The advantage is, if the price goes down you can get the lower price all the way up to two days prior to sailing. You can book Fun Select and still obtain the lower price all the way up until final payment is due. You can also book Fun Saver which is just like Fun Select. Fun Saver is a little less expensive but you don't get to pick your cabin. You will receive a cabin at the level you picked or better, but not worse. Again, if the price goes down you can get the lower price up until final payment is due.
In all cases if the price goes up, you can keep the old lower rate. However, if you don't book and the price goes up you cannot ask for the old lower rate. So, it is always best to book as early as possible. However, if there is a chance you are not going on the cruise, don't book the Early Saver which has a non-refundable deposit.
Thanksgiving is a popular time to cruise, so most likely the price will increase. I have two cruises booked with Carnival. One, in February 2011 has more than doubled in price. The other, over Thanksgiving this year, has increase about 1/3 since I booked.
Anytime kids are not in school is a popular time to cruise. Holidays (Christmas, New Year, Independence Day ...) are also expensive times to cruise.
3) Since you are not sure of what you are doing, I recommend you book with a travel agent. Find one you are comfortable with (online or brick & mortar). Interview several. Look for one that is a member of at least one of the professional organizations such as CLIA (Cruise Lines International Association) or NACOA (National Association of Cruise Oriented Agencies) or NACTA (National Association of Commissioned Travel Agents).
When you speak to the travel agent, see if (s)he is willing to spend the time to answer your questions. If (s)he asks questions about what you are looking for before recommending a cruise. If this person tries to steer you to one particular line it might be better to find a different agent. Also find out what the agent's cancellation policies are. Does the person you are speaking to have any personal cruise experience?
If you book direct with Carnival, be aware that the people you are dealing with will only recommend a Carnival product and some do not know their own product.
4) The cruise only goes as far south as Ensenada, which is about 75 miles south of the border. So the weather you are concerned about is very similar to the weather in San Diego.
5) The cabins can sleep two, three or four. How many each cabin sleeps is listed on the deck plan.
6) Carnival does not have two room suites. However, with a roll-a-way bed you might be able to put five in a suite (this is something your travel agent should be able to help you with). However, price both ways. Sometimes it is less expensive to get two cabins than one suite.
Here is a link to my review from my July 2008 cruise on the Paradise ... http://www.cruise-addicts.com/reviews/readreview.php?id=394
The following pictures are from my cruise on the Paradise in July 2008 ...
An ocean view cabin (U166) ...
