Yes, "Guinea pig" should be capitalized as it is a proper noun referring to the animal species.
Yes, Was it a dog? Hahaha It WAS capitalized! Was can be capitalized.
Yes, "I am" is typically capitalized because "I" is a pronoun and should always be capitalized in English.
No it shouldn't be capitalized. Seasons aren't capitalized.
Yes, "Football" should be capitalized when referring to the sport in general.
Yes, "Malaysian" is capitalized when referring to the nationality or language of Malaysia.
Guinean Sports are very complicated, so bear with me. When you buy/adopt a guinea pig, obviously they are very fat and/or obese. So some people put guinea pigs into competitive sports... and there is your answer.
A Bissau-Guinean is a person from Guinea-Bissau or of Bissau-Guinean descent.
Guinean franc was created in 1959.
Guinean syli was created in 1971.
Guinean syli ended in 1985.
Guinean puffer was created in 1838.
New Guinean mark ended in 1915.
New Guinean mark was created in 1884.
Equatorial Guinean ekwele was created in 1975.
Equatorial Guinean ekwele ended in 1985.
Guinean People's Union was created in 1958.
Portuguese Guinean real ended in 1914.