Baggage question when flying delta?

me, my husband, 2 cats, and 1yr old will be flying delta from hawaii to nc and because we are moving due to military orders we get 3 bags up to 70lbs but my issue is carry on bags and carseat. i have read that bc the carseat is large the person in front wont be able to recline and seeing as how the army paid 1043 for her a seat i don't think its right of others to complain but will this cause a problem? also bc of the time of yr we have to ship our cats in cabin so that counts as a carry on taking both me and my husbands alloted bags. does my child get a carry-on? is it by the seat or person b/c she cant carry it? i will have a cpap bag and medication and insulin and needles for myself which doesn't count as a bag but does a diaper bag? does this mean we will not get any carry on bags allowed? thanks in advance