Well, more Czech 4.7cm Pak 38(t) could have had production continued with if the Pak36 was found even more lacking than OTL
Indeed, but in OTL only 159 czech 4,7cm guns were produced in the second half of 1941 vis-a-vis the 555 pak 36. I suspect such a thing happened because it would be a huge and temporary investment of massively expand the 4,7's production when a better gun is on its way. If the Germans expand the 47mm production, then the pak 38 will have an even lower rate of production.
German war economy had severe limitations in what was possible to be done and how quickly. Germany was not USA with its incredible industrial potential - and even the Americans had limitations until early 1944.
I really doubt Rommel could maintain the roadblock TBH. I think the only chance he really has to break the British would be to attack as the British send a force back to try to break the roadblock, but I don't know if that's practical.
I think so as well.
When the 5th Leichte arrived, it had just 95 Pz III and IV. It was basically a beefed up panzer regiment. They lost already a fair number of tanks when they tested the british defences when they arrived at the front. I don't think replacement tanks could have been sent, since all shipping available would be dedicated in bringing the 15th Panzer in Libya, especially since in TTL there is only Tripoli as a port. The British are overextended, eye. But I firmly believe the 5th Leichte is even more.
There is also the fact that Tripoli is within bomber range and Malta Convoys will be staged from Alexandria with Cyrenaica providing cover for a significant part of the trip. Hurricanes can fly directly to Malta as well. In any case, Fliegerkorps X will move to Greece even without a Battle of Crete, since it is much more important for german interests than Malta.
Malta can be reinforced and developed as a major base much quicker. For example, before Cyrenaica was overrun by the Axis, 6 Hurricanes of 274 Squadron had flown there. Without Cyrenaica hosting Axis bombers, the base equipment and personnel of the 274 Squadron could have been transported there, especially since there is land air cover. The rest of the squadron's fighters could have easily arrived as well. There is no reason that by May-June 1941, Malta cannot have 4 instead of 3 fighter squadrons.