With the mess, if we're eating something that I know is going to be messy then I'll put a terry cloth nappy underneath her bib and over her legs, so whatever is spilt down her front goes straight onto the cloth and keeps her clothes clean. Then just fold up the cloth once you're done and go shake it outside. Our main problem atm is DD throwing food...she has a pretty good arm on her so it tends to fly a long way

Try not to let it get to you...can you get a plastic drop cloth or old sheet to put under her high chair as well so any food that goes on the floor falls onto that, leaving your floor relatively clean.
In the early couple of months of solids I found the Rafferty's Garden pouches of food really handy, especially on days when you don't have time to prepare food. They don't have any additives/preservatives and taste pretty good! Even now I still use the fruit ones to mix into yoghurt/cereal and they have smoothie (fruit & yoghurt) ones as well. I only buy them when they're on special though

For vegies I just used to save some vegies from our dinner the night before, that way I wasn't having to prepare & cook them for before she needed them, just pop them in the microwave so they aren't so cold and off you go. freezing food in ice cube trays (like spag bol mince) was really helpful too, just pop a couple of cubes in the microwave until defrosted.