Yup, avoid the temptress of the fabled "Blue Ho".
Other than that, Belize is your oyster.
Most of the resort dive ops do entail a 20-30 minute boat ride, but it's largely in sheltered waters. They are smart guys, they will give you the best experience (as most anyone worldwide would) dictated by immediate weather conditions.
Most readers here would not be diving out of Belize City or mainland ports. That is a Cruise Ship thing and quite a thrash of a boat ride. A week spent on the mainland is
not high on my list of things to do. Most SB folks go to stay at week-long resorts on the outlying Cays. Some, as you referenced, do liveaboards.
I keep reading about very long boat rides, live aboards, rough conditions, lots of current and remote resorts
Fairly average boat rides from resort to dive site if you compare this worldwide.
Live aboards? Not sure what would make them an issue... were you considering one? I'd say, go for it! It is expensive, but it is the only way to get many many logged dives in a week. It is not as relevant in some very few destinations as a hedge against weather (easy to move to avoid wind/wave) because the effect of weather in Belize is universal. The other plus to a liveaboard is moving to give you variety. In Belize, I think this is a non-issue, all of the out-islands are as good as another. They really pour it on thick over giving you an easy long trip to the Blue Hole which can be easily researched (an oft discussed topic here on
SCUBABoard), because in reality, this is the only big difference that they can offer, other than
the real holy grail of 4 and 5 dives each day.
A liveaboard is a great thing for new divers, especially ones that operate in the conditions of Belize. You have to decide what you want... a vacation with diving (available more cheaply on land based resorts) or a full blown dive boot-camp (much easier on a liveaboard). Depends on how you want your learning curve to accelerate.
Rough conditions? Belize can get a bashing, no less than Cozumel, in the Caribbean Tropical Storm season. I would be most concerned in the months of Sept-Nov and again in the first 1/6 of the year (Jan/Feb) when "Northers" (cold blasts from the US) come pushing down... like when it gets cold in Texas. There are ways to play the Caribbean even during this season that many think is carved in stone: Hurricanes "guaranteed" from August>November. Hogwash.
Would you recommend Belize as a diving destination for newbie divers?....with only about 30 dives so far, in Hawaii, Cozumel and Costa Rica.
Most folks with that dive history would place themselves firmly in the Navy SEAL category. It is never the raw number of total dives one has, it is more a measure of the breadth of your experience in different conditions, both of the sea and considering different dive op boats. Sounds like you've had more than enough experience to me.
Belize diving has lots going for it. Lots of good viz, interesting reef shape architecture, white sandy bottoms that really brighten things visually. It really rewards the more advanced divers who have learned close-in observational skills and have perfected their buoyancy. Getting in close for a look-see at the little critters on the reef is what these shallow Sun lit walls are best used for.
Most divers are usually agog at simply being underwater, or finding Lobsters. That's why reef shapes are a big deal, same thing as a "shipwreck"- they are easily identifiable and give 85% of the divers something (anything) to look at. This also explains the fascination of the Blue Ho dive site. It is simply just very easy to see.
Follow a good naturalist DM and advise them in advance of your skills, experience and any doubts. Listen to the dive briefing as if your life depended upon it. Take this opportunity to do at least two night dives. It is an excellent area to do this, and on the first one, you likely won't remember much... do two.
Belize, as with other similarly situated (worldwide) resort destinations, responded well in it's dive-op's behaviors and methodology due to the character & skill sets of the visiting divers. They are used to us bumbling Northerners coming down and trying our best to be good divers. I thank them for not snickering (out loud), but our standard type of visitor has taught them what to be ready for, how to react, how to make sure we live through the experience... maybe even enjoy it.
Oh, did I mention that you might not want to dive the Blue Hole?