Typically SeaWorld Orlando rides don't hold long lines (Sesame Street area can be an exception).  Manta is usually running at park open.  Hit it early since it will keep a line for much of the day due to location. They often hold the back half of the park for another half hour or so.  I believe they have 3 shows now (Sea Lion, Orcas, Dolphins) and all are worth catching.  Show up 15-20 minutes if it's a Saturday and busy.   The Sea Lion show usually has a mime for 10-15 minutes before the show starts.  He's usually pretty funny and worth showing up early for.  I've never had trouble doing all shows and rides multiple times unless bad weather moves in.  Adjust your arrival time to shows by the crowds.  If it's crazy busy, arrive super early.
Problem with all day dining here are lines.  On crowded days, you'll spend a good amount of time in line.  Slow days you risk many places being closed.  I used to always recommend the daily dining but prices have really increased lately.  Smokehouse sampler was always a go to for me and the wife.  Tons of food.  The dining place in the arctic section is usually pretty quick and has asian food, pizzas, and something else, I believe. 
Everyone loves Pipeline.  Mako is top tier.  Manta is great.  Ice Breaker is not my favorite but better now that they've modified the restraints (same trains as Tigris but they removed the 2 collar straps).
SeaWorld is one of America's best parks.  Hope you have a good visit.
If you want to ride something crazy hit up the Orlando Starflyer after SW.  Those swings are nuts and scare me to death.  Only done them once myself.