1999 Chevy Astro brake light switch

1999 Chevy Astro Van mileage: 64,000. I am at a loss here in more ways than one. Overall, my 1999 Chevy Astro mini conversion is in great shape. I take care of it, regular3,000-mile oil changes, etc. My issues: First, I have had an intermittent problem for the last year shifting from park.I have just replaced the second key ignition switch and had it to a mechanic twice in the last week. It starts every time. I apply the brake and sometimes it will not shift out of park (shift lever locks up). After 5-30 minutes of wiggling the key/pressing the brake, it will allow me to shift out of park. I checked around the steering column under the dash, located a round black cylinder, and discovered it gets hot. I think the problem is some sort of switch or solenoid that allows the shift selector to shift after the brake is applied. When it does shift, I can hear something engage, when it does not, I don't here anything. Help?Second, maybe you have a suggestion for me as recourse. In the last 3 weeks, I have spent nearly $950.00, some on normal tune-up and brakes (rotor) I did myself, and most on major repair. The shocks were bad and the tires were (cupped) ruined, due to the idler arms. This was confirmed by two different repair facilities. I discovered my extended warranty ran out 45 days prior. Three weeks ago, I replaced tires/shocks and idler arms again. The idler arms were replaced at a GM Dealer by a Goodwrench mechanic 18 months prior under warranty.I contacted the dealer and GM, neither would do anything for me, citing 12 months 12,000 miles warranty on their idler arms. The road hazard warranty would not replace my tires due to damage caused by the idler arms. The 70,000 Mile Goodyear Regatta tires had around 40,000 miles on them.I do not know of any one replacing idler arms every 18 months.