if we compare, for instance, the number of endemic land-shells in madeira, or of endemic birds in the galapagos archipelago, with the number found on any continent, and then compare the area of the island with that of the continent, we shall see that this is true.

How would the previous sentence be correctly capitalized?
Answer: If we compare, for instance, the number of endemic land-shells in Madeira, or of endemic birds in the Galapagos Archipelago, with the number found on any continent, and then compare the area of the island with that of the continent, we shall see that this is true.
all the apartments have one or two bedrooms with one or two bathrooms, as well as a kitchen and an external and private area.

How would the previous sentence be correctly capitalized?
Answer: All the apartments have one or two bedrooms with one or two bathrooms, as well as a kitchen and an external and private area.
this experience occurred on the sun 29 jun 2014 00:00

How would the previous sentence be correctly capitalized?
Answer: This experience occurred on the Sun 29 Jun 2014 00:00
but she has recently met a new man she fell in love with; therefore, she turns to the doctor, it all ends with gabriel glass falls for her.

How would the previous sentence be correctly capitalized?
Answer: But she has recently met a new man she fell in love with; Therefore, she turns to the Doctor, it all ends with Gabriel Glass falls for her.