Add spaces: Thesubscriptionwillrunfromthedateoforderinguntilthechosenperiodisatanend.

Answer: The subscription will run from the date of ordering until the chosen period is at an end.

Add spaces: ...excelinsimplicityandeleganceandnearlyallofthemtreatsubjectsofgreatimportancetomarkedadvantage.

Answer: ... excel in simplicity and elegance and nearly all of them treat subjects of great importance to marked advantage.

Add spaces: LakeKivuisoneoftheworld'sthreeknown"explodinglakes,"presentingathreataswellasanopportunityforlocalcommunities.

Answer:
Lake Kivu is one of the world's three known "exploding lakes," presenting a threat as well as an opportunity for local communities.