1. There are TONS of threads about washing and reusing yeast. Search.
2. I wouldn't really suggest reusing any yeast from brews with heavy adjuncts (eg pumpkin) as the yeast likely has worked a little harder and may have adapted in strange ways
4. You're washing yeast to reuse it and then adding more yeast to it?? I don't get it.
5. I always build a starter when using washed yeast. First, it lets you know if the yeast is even viable and not ruined, and secondly, since you refrigerated it (right??) the yeast is dormant and needs to be fed before dumping it into wort.