Procraft w/Merc 300

[300Procraft]

I have a 2002 300PM on a Procraft 20 foot fish and ski (bassboat with an extra row of seats). What is the best height to set the outboard? If I set it low, will it help lift the bow to increase speed (more bite)? What size fuel line should feed this motor and are there screens or filters that may restrict the flow if dirty? I can't spin this past 5800rpm even when I drop my prop pitch and it bogs on take-off until it planes off.

Any help would be appreciated!

Thanks