For many buggy owners break downs are occupational hazards and as you say nearly all are small things - rattling loose, breaking because they are badly made after market items or simply the natural temperamental nature of old engines.
Glad to read you realise any thoughts of throwing in the towel are unwarranted for the joys of driving an open topped buggy.
Ideally you keep using your buggy regularly so it has less chance of forgetting how to run properly, try and spot developing issues and, best of all, hang around with other buggys as there is definitely the power of the crowd in solving break downs.