I think the problem you'd face early on is the limited range of colonial cards you have to play with. Those early ones - missions/trade posts etc are good for setting down a marker of interest but I found (with Italy) that none of them really push colonial penetration over 35%. At that stage you will achieve 'colony influenced by' but not be able to progress.
For Italy, this is mostly resolved on unification (but as Italy is deemed a regional power in the game you are still limited). For Germany, if I recall, its actually a set of 1880 or so events that trigger the shift to colonial expansion (ie the historical fall of Bismarck). At that stage you get, by event, the historic German colonies in E and SW Africa plus bits of the Pacific. You also get the full range of cards, including those that really allow you to push your colonial penetration up (colonists, transport improvements etc), so can move into new areas as well (the AI tends to leave West Africa as a complete guddle so there is scope there for example).
How you feel about this is a matter of taste. If you manage an early unification and there are still lots of obvious targets in Africa then would Germany have been as cautious as it was? If you feel no, have a look at the 1880 colonial events and perhaps script in the range of cards for an earlier date. You may still find not all can be accessed due to Germany's orientation - I'm not sure if it starts as a regional power then becomes global by event (check this on the F1 screen), but even with this limit you can start to make progress - a useful target may be the wider east coast and Yemen (coffee and opium are very useful to grab), I snagged this entire region for Italy and it really eased my problems with luxury goods (as well as making me the chief drug supplier in the world ... but we'll set that to one side

)