Regarding whether you will be faster or slower than in a pool. I don't think OW swims in tris are measured that accurately (or measured at all). I have done the last two Worthing tris and i was quicker on the first, despite being faster in the pool around the time of the second. Most were slower in 2014 than 2013. At a seperate oly tri, the billed 1500 turned out to be about 1850. I reckon organisers just put the bouys in and think yep, that's about it. Or do they canoe round several times with gps and really try and make it spot on??
I did Outlaw last year and ran 10 miles on the saturday afterwards and a 40 mile fastish club ride the next day. Felt really good. If you've been training/racing for years, reckon you'll be fine. If you're a newbie and have a newly built base, give it a miss and concentrate on the Outlaw.
Done the Worthing Oly for the last two years. Great race. I will miss this years as doing the Outlaw on the same day. The early start means the sea is generally flat (was the last two years), bike course is fast with no nasty hills, just a few long drags. Raw Energy Pursuits who put on the race are great, as are the local tri club Tuff Fitty Tri Club. Enjoy.