tracey, it seems that your son will infact eat lumps, that's what he's doing when he has quavers, biscuits,, toast etc....I guess it's the more liquidy, cooked food with lumps that he finds a bit more 'odd' but I certainly found that ignoring any 'gagging' and ploughing on ahead worked in the end with my DS.
I think you just have to keep presenting him with the foods you want him to eat - if you want him to eat your homecooked food, JUST present this. Don't even buy the babylicious stuff if you had rather he didn't have it. You are in charge of what he eats, in that you can't force things in his mouth but you CAN only give himstuff you want him to eat.
If he eats almost none of a homecooked lunch, take it away but don't mark it down as a food he won't eat - I think you are right not to make an issue out of it as you don't want stressful mealtimes, but you must keep trying with the type of food, don't give up on it because he refuses it..Fruit can be given later if he gets really hungry before the next mealtime.
Don't assume he won't eat a food just because he refuses it - my DS had about 40 boiled eggs put in front of him and refused them ALL until one day he suddenly went for it. I just keep on presenting to him the foods I want him to have, sometimes it takes WEEKS but he always tries things in the end.
Don't assume he won't eat your homecooked food - he will, I'm sure, you just have to be really really determined. ..