Should i pop a small burn blister (few mms diameter) or leave it and apply silver sulphazidine on it?

Do not pop: Apply silvadene (silver sulfadiazine) and allow it to heal on its own. Popping it risks superinfection of the wound.

You can pop it: There has been much debate about the merits of "popping" (eg. Preventing traumatic rupture, reduction of pain) vs. Not (eg. Biologic dressing). Most burn surgeons now support unroofing blisters and using Bacitracin or polysporin. Silvadene (silver sulfadiazine) is an alternative, but the white color prevents visualization of the burn.

Leave it: Apply Bacitracin once a day, keep area clean. Leave blister intact.

Leave it: Right now the blister is essentially providing a biological bandaid. Once the blister is open i prefer to use silver sulfadine to prevent infection and aid in resurfacing.

Protect it: An unpopped blister represents a closed sterile environment. Yes on occasion one can become infected then it is time to open it, however the risk of infection in a dressed open wound is still higher than that of an intact blister. The blister will gradually resolve with time i wouldnt use an ointment on blisters at all silvadine no help now.