Are you trying to see Seattle or are you focused on the nature aspects of things? Saint Helens and Olympic are jaunts and I'm not sure you really want them to be day trips... It matters because if you're trying to see the mountains you're probably *not* staying in Seattle proper imo.

Also of note: Rainier in July is *full of cars* and if you're going to visit you would be wise to try to get there early (like 8-9am) before it becomes a giant traffic jam there, which it tends to that time of year.

Looking at staying 6 or 7 days. I am more interested in the nature and National Parks but don't mind seeing a little of Seattle. I will see about renting a car and I'm not afraid of making full use of "unlimited" milage (you should have seen how many miles I put on a car in Hawaii)

If you want to establish a "central base" and take day trips from it to see nature and the national parks, I'd probably get a hotel in Olympia tbh. Maybe Tacoma if you're looking to spend some time closer to Seattle, but Olympia if you're looking for closer to nature (take a day trip to like Aberdeen and Ocean Shores for example).

Leavenworth is a nice area to visit for a sort of renaissance style nature spot. It is a bit touristy especially during the summer time. But I'd say it's worth visiting nonetheless to experience some of the cool stores and the general area/views. If you want a less tourist trap area, North Bend is a very beautiful spot next to Mt. Si and Little Si that are awesome hiking trails that won't take up the entire day (depending how fit you are of course).

During the week, I-5 next to Tacoma and next to Seattle proper will be very very busy especially during rush hour from 3-6 PM and 7-10 AM. So I would avoid those if possible. Doubly so going NE on I-405 towards Snoqualmie passing Bellevue. I-405 has truly gotten atrocious over the last couple years that's actually worse than I-5 during peak hours.

If you want small hiking spots, Poo Poo trail, Rattlesnake Trail, and Mt. Si are some pretty good spots with a good view at the top. If you want a bigger commitment or an all day hike, I would look into "The Enchantments" https://www.wta.org/go-hiking/hikes.....hantment-lakes. Very beautiful set of trails going through lakes and mountains and has a lodge right at the trailhead you can book if you'd like. If you want to camp at one of the lakes, you would need to get a pass that goes through lottery in February and is around $20-30/person I believe. Best advise for you to scope out some hiking trails/mountains is to download the AllTrails app and look around some areas for some perspective trails to go to. Area Olympia to the East and SE is a good spot, East of Seattle is probably the majority you'll see near Mt. Si and Tiger Mountain. There's SW as well that's a good ways west of Olympia and South of the Navy Base in Bremerton that's not as popular but still a good spot too.