How much access to engine types should we have?

[Arakash]

So put simply:
-Standard scenario would give you basic access, but require research for anything unique/strange at the time.
-High Tech Engine Scenario might give you immediate access to a number of strange engine designs, representing a group of pioneers in the field.
etc etc. (many other options for this)

I think this could get expanded into some background system.
At the start of the game, one could choose their character's background, such as Engine Pioneer you mentioned, giving one access to more engine designs, or Renowned Manager, lowering the administration cost, or Lottery Winner, giving one some additional cash, etc. etc

Of course the feature could be disabled if one wanted a bit more challenge, and the benefits would be lower with higher difficulty levels.

Sounds good.
If your interesting in discussing background/starting scenarios in depth, there was a long discussion on it here you might be interested in.