Steve,
I started out with a very similar setup.
It's important to know the boat and engine limitations and like you say know the weather.
There are plenty of fish in the harbour and close to the shore so there is really no need to push the limits and head for the horizon ( suppress those urges for safetys sake)
it's still earlyseason but there will be fish right under your nose
for weather/tides i use Windguru .com ( select avon beach) and easytide.
The two main bits that can catch you out will be the Mudeford enterance and the Hengistbury Head Groyne areas which can chop up at times.
I have fished the ledge ( 1-2 miles out)in such a set up but only in flat calm conditions and on neap tides
Hope this helps
PJ