10 days is kinda long for gold coast alone. RM2.5k? not a big problem.

1) Theme Parks (i spent 1 day at each theme park, 2 at dreamworld, separated wet and dry for 2 days)
a) Warner Bros movie world
b) wet and wild (water park)
c) Sea World
d) Dreamworld (they have both wet and dry, their extreme rides are supposedly one of the best)

2) Beach & City
You can do it during late noon and evening, it's a city, no big deal. and the beach, so and so la. You don't need one day to visit the beach in GC

3) Accommodation
You can get cheap apartments. Few areas you can look into, Mermaid Beach, Surfer's Paradise, Broadbeach, Palm Beach. Let's not stay too near the airport, cause it will be too far away from SP. SP is the supposedly city centre i suppose. Convenient but not necessary to stay there.

My recommendation? Palm Beach Holiday Resort

I booked a 2 BR apartment, under $100 per night (in 2011). 1 double bed room, 1 room with 2 single's bed, plus living room, easily can house 4-5 ppl if no one minds the living room or triple on a double bed.

Pros: near to supermarket, big and cheap, it's just next to the beach. bus pick up point is only across the road. see 4)
Cons: slightly further away from SP compared to Mermaid Beach or other areas. and you will be one of the first tourist to get on the bus, cause the bus starts from south to north then to theme park, see 4)

4) Transportation

Rent a car... or just buy their 'bus' pass. unlimited travels on their special bus and public bus.

australians know what they are doing, so they arrange these buses, which will bring you from your accommodation to the theme parks. these are not exclusive buses, but they will have certain pick up points (strategic points) then pick up all the passengers that they are supposed to pick, and drop you at the theme parks, whichever you requested. all you need to do is call the bus company the night before you want to go to the theme parks.

5) out of GC, north to... brisbane? or south to... byron bay?

Brisbane, been there, some city, not too interesting. Just a city.

Byron Bay, never been there, you can do your research. that's the furthest most interesting place you can go.

to me, the main attraction in GC is the theme parks. so for me, it's like 1 day 1 park, probably another day for city and beach, though it can be squeezed in before/after you depart to the theme parks anyway, early morning and late evening stroll on the beach. if i would to recommend a trip... 7 days max. also because the bus pass comes in 3 days, 7 days, and some other combination.

1) I have no idea about wildlife park in GC. if it's a first trip to australia, yes, it's only right that you go to a wildlife park to hug a koala and feed a wallaby/kangaroo.

Well, based on the location, Currumbin is easily reachable. The few things you might want to take note is, if they charge extra for ‘extra’ activity. Example, some parks will charge for taking photo with koalas (they don’t allow you to use your own camera), some totally up to you and free.

I can provide another option, which is Australia Zoo which is Steve Irwin, crocodile’s man zoo. That is north of Brisbane, which is far-ish but again, not a problem if you REALLY want to go there. I’ve never been there myself, so you have to do your own comparison.

2) Beach… I have no idea. The best beaches in Australia aren’t in GC. Though I once overheard a China Man uncle saying… ‘Now I know why it’s called, Gold Coast. When I was on the helicopter, moving along the coast, I can see that it is Gold Coast.’

The place I stayed, well, the beach was decent. You know, sand and sea water. Haha… I think GC beach is normal. I’m sure redang/perhentian wins. But still a good place to relax and enjoy.

3) Nature trails in Australia tend to be described in a way that doesn’t justify paying for it and going for it. Coming from a tropical country, nature trails in Australia tend to be normal. Just need to make sure it is really special. I’ve not done any in GC.