I see no problem with sieku. Just stay with the herd and you should be fine. I would suggest a VHF radio on board. Kinda fun to listen to the chatter on occasion and should you encounter trouble at least you have a way to get some help.
Salmon (especially kings) can be had very close to shore at sieku. You sometimes have to run out a bit for silvers, but once again not to far and it should not be a problem, as you will have company. You can run down near the mouth of the sieku river to try for halibut. My son caught a 37lb halibut right in the mouth of sieku bay on a tide change while fishing for kings a couple of years ago. We did not have a gaf onboard my little 14ft aluminum so we just hauled it in with the net. It was just about dusk and it took a couple of runs before we could get a look at what was on the end of the line. Lots of fun and a bit of a spectical watching us try to subdue the thing in that little boat! Have a great time and don't worry, you should be just fine.