am i getting the most out of my workout?

Hey everyone,

So the only way i could fit the gym in to my busy life was to go on my lunch breaks. luckly for me, they built a brand new lucille roberts about a mile from my job. so my new routine is.. 1pm i start on the elliptical and set it for weight loss program.. i put my weight and age and it automatically sets the program for 30 min. basically i am doing intervals of level 1 for 6 min, then level 8 for 6 min. my heart rate is averaged at 165 which according to the machine is above fat burning and in peak to high mode. i usually start off at a good pace.. not pushing or fast.. then after the 6 min the resistance changes to 8 and this is where i push and go faster.. i do feel the burn, i am sweating, and pretty much out of breath no matter how much i control my breathing. is this good? i know this means my heart rate is up and i am in fat burning mode. but should i push? or go steady throughout the whole interval changes? after the 30 min i move to the weight machines.. i do inner and outer thigh, flys, abs, and deltoids?? i think it is.. here is my issue with the machines.. i heard less weight more reps is for toning, / fat burn.. more weight is to bulk up. BUT... if i use less weights on the abs for example.. i dont feel a burn, i dont feel like i worked the muscle.. therefore i increase the weight to 55 lbs and i have to really focus on isolating the muscle.

once i am done with my workout.. i go back to the office and eat my lunch. hoping that this is the best time because my metabolism has the extra boost...

my questions are.. am i better off pacing the elliptical or pushing myself to the point of pass out? should i stick to less weights even if i am not feeling a burn? and, is it best to eat lunch before or after a workout? i am just trying to get the most out of my workouts and make sure i am getting them done right in the end. ohh i forgot to mention that i workout during lunch for 1 hr 5 days a week. and on saturday morning i take the kick boxing class then followed by total body workout..(which is not cardio..but more muscle building and strengthening).

thanks!