1a. Naturally and by design. The data might not necessarily be available and the program is not going to make that assumption. The data loading range is king; just get used to the idea that there is nothing before bar 0.
1b. Yes, that's by design. See the Wealth-Lab User Guide, Strategy Window > Backtesting Strategies > Inside a Portfolio Simulation >
Note on Lead Bars.
More insight into the problem:
Lead Bars & Position Sizing Leeway.
2. It's always a good idea to search the forums first or see the FAQ:
FAQ | Strategies and WealthScript > Optimization > "Why Sharpe ratio is not provided in Optimization Results?"
Even though it says optimization, its 2nd paragraph applies to Strategies as well.
3. That's right. You can choose from the following alternatives:
* By running multiple optimizations in different Optimizer windows
* By running Genetic optimizer or Monte Carlo method (both are faster)
* By breaking up a long running optimization by parameters
* By breaking it up by date ranges (1st half in one window, 2nd half in another)
* By developing a custom parallelized Optimizer (preferred, substantial development effort)