Hmm, so German strategy is expeditionary warfare on the scene of Morocco and Africa itself, plus a narrow frontal push on the French border alone, and it will be compelled to do defensive operations against Russia.
Something along those lines, yes. The German plan could be quickly defeating the French Navy, attaining a favourable situation in Africa, repulsing initial French and Russian attacks in Europe, then making peace with favourable conditions to them (maybe through British mediation). The Germans would essentially try to replicate what the Japanese did in the Russo-Japanese War. Wether their plan would succeed or not is another question.
British neutrality and French naval defeats could encourage the Italians to join the war, which would greatly increase the chances of German success, but it could also risk further escalation. The French might be willing to give up on their ambitions in Morocco if the Germans give them a bloody nose, but losing Morocco AND Tunisia at the same time might be a too hard pill to swallow.
A dragging war would greatly benefit the British. Not only would their chief rivals drag each other down (securing Britain's spot at the top in the process), they would also have the opportunity to trade with and supply both sides (the Germans could hardly be able to block Franco-British trade, even if they dominate the seas in the conflict). A-H could also make a bank supplying Germany (and Italy), but it could also exploit the gaps in the world market (created by the war) and expand its industries.
The Russians would hardly be willing to fight for French interests to the bitter end, they would act as a counterweight to French stubbornness. They would force the French to make peace if a reasonable proposal (in accordance with the facts on the ground) would come forward. Alternatively, Posen could be made a declared Russian war aim, however that would certainly lead to Austro-Hungarian involvement, which go against the wish of the OP.
Further escalation without A-H being involved could come in two forms:
1 - The Ottoman Empire joins the war against Russia to reclaim lands in the Caucasus (read: to distract the population from internal problems)
2 - Germany introduces USW and manages to piss off the British so much they join the war.