Toyota Repair: Keep old or buy new?, wheel bearing repair, oil leaks

Question
Hello,

I have a 2002 Toyota Sienna which has done about 120000 miles. In the last year I have spent the following on repairs:
Brakes , Rear - $355
Install Mirror - $105
New Tire - $50
Wheel Bearing Repair - $300
Total - $810

I have been told I have 2 oil leaks now, one near the timing belt which will cost approximately $500 to fix and one near the oil pan gasket which will cost approximately $200 to fix. I don't believe these leaks are bad as I have not had to add oil for quite some time.
Recently my check engine light came on. I took it to Toyota who said that it is the catalytic converter which needs to be changed. This will cost $680. I would then have to drive it for 500 miles before the check engine light can go off. Does that make sense? In the meantime my car is due for an inspection this week. Naturally it cannot pass inspection with the check engine light on.

In addition to these problems, my car stalls in very hot weather. This is very rare and only happens when it is heatwave weather, and after a couple of minutes it seems to start.

Money is very tight now. Car payments would be a big burden. I am also not sure how much sense it makes to make all these repairs on an 8 year old Sienna which has done 120000 miles.

Please let me know what you think.

Answer
I think those oil leaks can wait but keep in mind that it's also due for the timing belt at this mileage, but again, both can wait for probably 10,000 miles more unlewss oil is really pouring out, which it doesn't sound like. Did the dealer give you any diagnostic trouble code numbers for the check engine light? I would need to know these. It's not uncommon for converters to fail at this mileage but having the trouble codes would help just in case they made a mistake or are trying to sell something it doesn't really need. The statement that you have to drive it 500 miles after cat converter replacement is nonsense, it only takes a couple of driving cycles to get the computer to pass the monitor test, that statement causes me to doubt the technicians credibility a little.
You may make it through the inspection by doing this just before taking it in, it may work and if not you've lost nothing. Disconnect the negative terminal of the battery, this will clear all trouble codes then drive it to the test center avoiding heavy acceleration or high speed driving, when you get there and the light stays off have them test/inspect see what happens.