In this time of money being short is it time to have one british superbike championship?

Apart from what has already been said.

Take a look at John McGuinness Virtually untouchable around the island,

But where is he in the track standings.

They are very different riding styles, few riders actually do both road and track racing. (successfully)

The bikes are set up totally different.

There would not be enough dates on the calendar to accommodate bringing both series together.

The best Superbike rider in Britain or the UK is the one who finishes highest up the pyramid that ends with World Superbike Champion. The Best Rider in the World being the MotoGP World Champion.

Simples

There is only 10 % of the BSB riders who will race at the TT / NW / Macua / Ulster etc.

So that makes the championship invalid.

There is plenty of money is BSB still.

With the 2012 rules making 100% of the superbikes "EVO" it will reduce the cost even more and add numbers.

Making "Road" racing & racing 1 title is really not needed in the UK.

But motor cycle racing is a big business; it makes money. Those that want to be involved can and in the long run it can be profitable if they spend enough money and have good riders. Padgett's for example would not be where they are today or anywhere near as profitable without involvement in racing. The more race meeting they attend the more they are known, it is called advertising..

Some riders love the IOM TT while other riders would refuse to ride there so on your idea the riders that refused could not score points from the IOM for a combined championship?

I follow your thought but think you haven't looked at it from other directions...