Here is a similar post I have done before on this but def use an over the stove micro to save space.  possibly an 18″ DW if really tight space.

https://justaskal.info/topic/what-is-the-best-spacing-for-the-working-triangle/

Could be normal, depending on the cycle. 4 hours would be the longest cycle, and the sensor readings in the tub determine to continue washing or not. The average is 2 hours fr cycle these days. Some units do have a quick cycle as well. Here is a great blog on it from Whirlpool’s own website addressing just this.

https://www.whirlpool.com/blog/kitchen/how-long-do-dishwashers-run.html#:~:text=How%20long%20does%20a%20dishwasher,heat%20water%20between%20cycle%20phases.

The age of the unit vs. the cost to repair is the concern. The average life is 10 years, so if it is, say $300-$500 to fix, and a new one is $1000, then not worth it. Just be aware not to throw good money after bad.

If you are handy and take safety precautions. Such as turning off the gas and unplugging it. You may be able to find the root cause, but at the end of the day, a qualified repairman is needed, especially if there is a wiring issue. Try to find any repairman who works on pro ranges as the majority of the mechanics are the same. Did you try the Viking servicer locator on their site?

https://www.vikingrange.com/consumer/wheretobuy/serviceLocator.jsp