Some of us use nutritionists, others of us learn a lot from books and other diabetics on sites like this. Nutritionists, like any profession come in all "stripes and sizes". Many, unfortunately, adhere to the ADA line which tells us to eat what many of us think are way too many carbs and to accept blood sugar levels that are too high.
You said the nutritionist you saw gave you ratios of insulin to carbs (I:C ratio) and insulin to lower BG (ISF). Do you use these? Ultimately nobody (especially someone you just met!) can "give you" these numbers. We are all different and you have to find out what works for you. Many of us have different I:C ratios for different times of the day. If your results are good (and YOU are happy with them - not always the same as what your endo thinks!) than you are doing something right. However, having said that, if you are dosing your insulin without having accurately determined your I:C ratio(s) and ISF(s), you will have problems. You might be eating pretty similar things for your meals so things are working, but if you vary your diet you need the ratios. You might also be in your honeymoon and that will change! Just FYI 1 1/2 cheerios and milk would be absolutely impossible for some of us to eat without ending up in the 200s, so you might want to look at less carbs for breakfast. You don't "need" starch - though many of us like it and eat a moderate amount. Actually carbs are often easier to process later in the day when it sounds like you eat very low carbs.
My own opinion? Books, and answering on here might be cheaper (don't know what your coverage is) but they also might be more helpful. I highly recommend Using Insulin by John Walsh.You might also find Richard Bernsteins The Diabetic Solution interesting (get the newest edition -2011). Also you mention the GI and GL. In my opinion, these things aren't terribly useful for a Type 1. What IS useful is learning to accurately count carbs (there are lots of sources of carb lists), and then to, through trial and error, compute your own I:C ratio so you can match insulin to food. In time you will also want to determine your ISF which is how much one unit of insulin lowers your blood sugar so that you can correct highs when they occur.
Ok, so how did you go into DKA and have an A1C of 6.2??? I guess maybe because the A1C covers about 3 months and your onset was very sudden??