When I studied Mandarin it wasn't hard to find a single authority that I could trust with all such questions. I did that so I could avoid worrying about too many questions like these which arise in Mandarin too.
Studying Cantonese now I am forced to be more "fault tolerant", and authorities - any one of which I could let myself trust in this way without hurting myself much - differ from one another and make mistakes too. One of my friends is a native from Guangzhou (I don't mind that at all), but she won't remember to write clearly enough for me to read, and I'm often not certain what tone or vowel she's using; she doesn't know any Cantonese Romanization (and doesn't want to learn any), so she doesn't understand how much she could help me with a little hand gesture to indicate the tone (as I try to write down what she's saying, so I can look up what she's writing!). :-) I could let everything she says be authoritative, but I choose to check everything with Cantodict. Another of my friends is a Hong Kong native who is really reluctant to write down "written spoken Cantonese" (like 唔). So, so far with her, I am learning - at her direction - both "written spoken Cantonese" and SWC with Cantonese readings. I don't mind too much because it appears to be practically necessary. And I'm not worried about its effect on my spoken Cantonese either, provided that most of my exposure is to real spoken Cantonese. For example, I always hear 食 sik6 but never 吃 hek3, but I'm looking at 吃 right now on this week's assignment. So I choose to put 吃 hek3 on a flashcard but 食 sik6 is the word I speak (and I choose to write it too). That's automatic enough that I needn't worry about it. (And lastly, accidently speaking SWC with Cantonese readings should be the least of my worries, and almost everyone would understand it anyway.)
I hope you find the right amount of flexibility and a trustworthy spoken source. Then, the answer to your specific questions would be "whatever my trusted spoken source says". (While continuing to use e.g. Cantodict to check it. I love the Android Hanping/Cantodict.) Good luck! :-)
Studying Cantonese now I am forced to be more "fault tolerant", and authorities - any one of which I could let myself trust in this way without hurting myself much - differ from one another and make mistakes too. One of my friends is a native from Guangzhou (I don't mind that at all), but she won't remember to write clearly enough for me to read, and I'm often not certain what tone or vowel she's using; she doesn't know any Cantonese Romanization (and doesn't want to learn any), so she doesn't understand how much she could help me with a little hand gesture to indicate the tone (as I try to write down what she's saying, so I can look up what she's writing!). :-) I could let everything she says be authoritative, but I choose to check everything with Cantodict. Another of my friends is a Hong Kong native who is really reluctant to write down "written spoken Cantonese" (like 唔). So, so far with her, I am learning - at her direction - both "written spoken Cantonese" and SWC with Cantonese readings. I don't mind too much because it appears to be practically necessary. And I'm not worried about its effect on my spoken Cantonese either, provided that most of my exposure is to real spoken Cantonese. For example, I always hear 食 sik6 but never 吃 hek3, but I'm looking at 吃 right now on this week's assignment. So I choose to put 吃 hek3 on a flashcard but 食 sik6 is the word I speak (and I choose to write it too). That's automatic enough that I needn't worry about it. (And lastly, accidently speaking SWC with Cantonese readings should be the least of my worries, and almost everyone would understand it anyway.)
I hope you find the right amount of flexibility and a trustworthy spoken source. Then, the answer to your specific questions would be "whatever my trusted spoken source says". (While continuing to use e.g. Cantodict to check it. I love the Android Hanping/Cantodict.) Good luck! :-)