I did an IBCA event in Houston two years ago. I don't know how I finished out of the 110 teams there since they don't do a print out of results, but I was not in the top 10 in any of the three categories (chicken, rib, brisket). So you can take what I am about to post with a grain of salt...
Ribs: at the cook I went to, they mandated all the ribs be turned in the same way. For us that meant St. Louis cut spares, laid in the box flat with the thick side to the left of the box and side with bone showing (pulled back after cooking) pointing to the right - like a book where the think side is the spine. We had to turn in 9 ribs (no more, no less), individually cut (no Hollywood cuts) with 5 on the bottom and 4 on top. Because they were stacked, presentation became less of a factor. They also opened the box and checked them at turn in...so if you had them wrong, they sent you back to do it right.
Sauce: the guys next to us said use very little. Glazed and bake it on (you know that already). Use it for taste...not appearence. I have heard conflicting reports on this, but logic tells me if ribs are being stacked, go easy on the sauce because it will smear everywhere.
Sweet vs. Savory: We went sweet. We didn't win. I know the ribs that I made would have scored in KCBS. Take it for what it's worth. I have tried some Texas rubs and found them to be salty. I have been told by cooks who have competed successfully in Texas to increase the salt taste to win....this would be dictated by region - in CA you would know better than I.
You can't trim brisket to fit the box (I don't anyway) and your slices should be the thickness of a #2 pencil, so bring one along. They opened up the box and literally held a pencil next to each slice at turn in at the contest I did to check the thickness.
Also, not that it makes a difference, but your turn-ins will go into the standard 9" clamshell with a foil piece inside. I think they also use plastic forks. As I mentioned, they told how many samples to turn in. Ours was 9. That was 9 ribs, 9 slices of brisket and we had to do 2 halves for chicken. The turn in for chicken was in a foil half pan instead of a clamshell. We have a lot of teams, which meant a lot of judges...so we had to turn in more. I think the min. is 6 samples.
Here are some pics of IBCA turn-ins. Not mine...but this is what I used in preperation for my first (and so far only) IBCA cook-off...
Again - Not my pictures...just a reference...