They tell you that they don't want anything except occasional sexual contact. If you are more attractive and engaged than they are with them. You can't stop thinking about them. You will make yourself heartbreak again. The FWB scene must be in a reciprocal friends with benefits with limited expectations. If you think you are ready for a loyal relationship, then don't rush into it.
Spending time on someone who has only a partial relationship with you will take up the time you meet with someone you can eventually build a partnership with. If you are embarrassed or insecure about friendship, then you are not suitable for this situation. What should be included in the affair dating rule? When you decide that you all agree to this nsa hookup, you must immediately talk.
Make sure you all know that this is a casual encounters and that there is no expectation of a deeper romantic/love relationship. You still need to talk about how often you see each other. Will you strictly use it as a sexual contact in the bedroom, or will you have an outdoor date night? Is there only two of you, or will there be other people involved?
You need to have a conversation in advance to arrange the time for the next meeting. Do you want to be exclusive with them in terms of sex? This should be a reciprocal rule, you are all on the same page. You need to respect each other's time. There is no last minute bail because someone or something happened. When nothing else happens, you won't use each other. You usually really like each other, you have to treat them as you wish to be treated. Another important question is: In this case, can you date someone else? They need to tell you if they are dating some other adult friend finders, or do you not know what the other party is doing? Will this be a secret situation or will someone else know that you are a good friends with benefits?
Fwb dating is not for everyone, and I am not sure if it is right for you. Before you make up your mind, you have said it yourself, you are not sure if you can handle the arbitrariness of all this. You still have to face the insecurities of being deceived. This open relationship will affect your self-esteem. There is no time limit or pressure in the case of nsa hookup, so as long as you honestly tell him your concerns at the outset, it is not harmful to try to see if you can handle this casual fwb dating.