I'll +1 on what Wisconole said; in regards to carbon blades anyway, I haven't used a Masamoto (yet), so I can't comment on that. But carbon blades are a lot more forgiving than they're made out to be. I remember when I took the plunge on my first carbon (Sabatier) and was hesitant as I was worried about it rusting up on my as soon as I turned my back on it after cutting a tomato. They reality is, they can sit for a long time before anything severe is going to happen and any unsightly discoloration can easy be scrubbed off without damaging the knife.
For example: My main workhorse is a Sugimoto #6 cleaver (white steel, carbon clad). I can happily mince 2 kilos of garlic with it (the boss doesn't believe in Robo Coups, don't ask me why) which probably takes about 30mins, then maybe another 5mins tops while I attend to packing the garlic away and cleaning the bench before my personal affects. If I leave it too long I might get some orange discoloring on the blade which I don't want, but I can easy take it off with a soft scourer and hot water in a few seconds. i like to think I cut an abnormal amount of acid foods in my work place (certainly in my personal experience) and I don't have a problem. It'd be even less of a problem in the home, due to the quantity being cut and hence the amount of time the knife is in reactive foods. Say you're making something like hamburgers:
Peel onion and garlic, bin scraps
finely dice onion, set aside and clean board/knife
chop garlic, set aside, clean board/knife
chop herbs (if you feel so inclined), clean board/knife
I find regardless of the knife used, I tend to wipe the the board and knife after each ingredient anyway in the interest of being clean; you're not going to start chopping garlic when there's onion all over your board and still stuck to your knife.
The only problem you may have with a carbon blade is discoloration on the actual food when the knife is new. My sabatier is probably the most reactive knife I've used, and if I bought another to use at work I'd probably force a patina, but I haven't felt the need with most japanese knives I've used (Sugimoto, Shigefusa, Azuma minamoto, Tadatsuna, konosuke etc). If it was a concern, just force the patina.
In regards to sharpening. I think most carbon knives don't have the retention of stainless knives (vague statement, I know), but I think most home cooks would still only sharpen their knives every couples of weeks tops, unless their particularly pedantic, I would probably only touch up my knives once a month before I started in the industry.
Oh, also welcome and it's good to see the Australian contingent growing on KKF