P0420 and battery charge screen

Hey folks

Just picked up a 2005 with 146k and full Toyota service history, although seems a steering recall was not done. Will run it to the dealer tomorrow to check.

I need to decide a.s.a.p. if I am keeping the car or not (I know the seller, he will take it back)

Anyway to cut a long story short, two questions.

1) Car had P3190 and P0420 when I got it. Seller reset, drove home and within 5 minutes on the road the CEL was back on. Checked the codes at home and see only a P0420. Much to worry about? Seems this might be big (Cat) or small (O2). Car getting great mileage - 60mpg at 60mph and it seems to be running great. Should I worry or forget about it? Note I am in Florida with no inspections.

2) Seems that on the highway the battery display on the energy screen is mostly minus the top 2 bars i.e. just in the blue. In town it creeps up to minus 1 bar, i.e. all green. I haven't seen it full of green bars yet. Does this imply that there is an issue here?

3) OK, 3 questions. I have a 400 yd driveway. If I pull up to get the mail at the road after a long drive home I can do the full 400yds at 10mph on battery only. Creeping this speed up each time so may get more speed out of it. But, when I start the car first thing and go to drive away I get 50yds tops before the motor kicks in. Again, anything to worry about? Or is cold start batter performance poor?

4) OK, 4 questions. What have the Romans done for us etc.... Car only has one key (and has Smart start). Best (i.e. cheapest and easiest) way to get a spare key made?

BTW Have done about 200 miles so far and it's behaving really well. As am I, as my other ride is a 540i...

Loved the Toyota owners site and ability to plug in a Vin and get the history. Hugely helpful and reassuring. Also, FYI, plugged my VIN into Google and up popped a link to a full carfax. Which was nice.... ;o)

Thanks all.