Regarding the political situation you are absolutely right of course. I was more thinking about the very difficult (and at times disappointing) way the german forces are heading in terms of transformation and modernisation.
Ad 3) possibly; but think of the spares deliviries!!!! That is where the money is made.
Thats the major official/public argument for giving away our tanks like that. It remains to be seen wether all these expectations will hold true though. Most countries that buy Leos now, buy some more in order to have spares right on the spot (Singapore is a good example), so their need for additional spares delivered by the german industry is comparably low. Mostly these purchases come with very little in terms of long-term maintenance contracts, so all you got there is hope and good faith for the customer to come back for more (or different) stuff.
Tank industry: What the world needs now is a good MEDIUM tank to replace the Leo 1.
I guess right now the focus is more with IFVs and APCs. The german industry has up-to-date offers in both fields, so I guess we can still look forward.
As for the Leo-1, most countries seem to replace them with heavy MBT, mostly refurbished Leo-2 or competitors like Abrams etc. The Russians are in for the cheaper or politically motivated offers. Although they are a primary example of a military force emphasizing lighter tank designs, this doesnt seem to be a decisive issue in evaluations.