Re: is it too late for a sling with a toddler? (what to do when cooking?!)
My initial response was a Mei-tai-like soft carrier, but after rethinking I'd suggest a ring sling (hip carry), because it allows your toddler to observe in a close distance without feeling too confined.
Personally I use a sling for DS's naps and household chores like vaccum cleaning, and a mei tai usually for outings and anything I don't want DS to reach.
Here are some good photos on the common problems of using a sling. I choose them because they were taken of a father and a son!
http://www.thebabywearer.com/index.php? ... ngproblems
By hip carrying I mean your son's legs will straddle one side of your hip.
I agree that cooking and wearing a toddler can be dangerous esp you are dealing with hot oil etc. When the work involved is not that dangerous, you can improve the safety more by shifting him backward so that he is behind you. But you still have to be careful: he may grab a sword without you knowing it!
A final note: your body may take some time to (suddenly) adjust to the weight of your son , and you may feel rather hard initially (OK if you just wear him for a while). Remember to spread the fabric on your back evenly so that the weight is not just distributed on the shoulder. I hope this helps.