Does pickwickian syndrome usually cause many symptoms?

Yes. Shortness of breath, difficulty falling asleep and staying awake, and eventually lower extremity swelling (edema) and eventually right heart failure progressing to death.
Yes... Pickwickian syndrome results in excessive daytime sleepiness, low oxygen level in your blood, cyanosis or a blue color to lips, fingers, toes, etc. A classic description is given in the pickwick papers by charles dickens and this is how the syndrome got its name!
Yes. Term; pickwickian syndrome comes from a story & is related to a morbidly obese patient with excessive daytime sleep, redness of face due blood, very likely with shortness of breath upon exertion, leg swelling, slow mentation due increased carbon dioxide in blood & low to borderline oxygenation.