To be clear, you recommend not using an entrance reducer, correct?
That is indeed the hard part of a new hobby; figuring out what works! The one thing that gives me comfort is that there is so much debate on entrance reducer use. It tells me that the restriction is only necessary if the hive is under attack, otherwise it is an insurance policy that probably adds some inefficiency to the bees lives.I would say the entrance size depends on the strength ( number of bees)of your hive ..small numbers can only defend a small opening, if your hive is big and full, open the entrance a little..if you watch them and see how they go in and out and doesnt seem to be a bottle neck, leave as is, if they are having to climb over each other to get in open a small amount at a time till it looks like they can get in and out without issue, also keep an eye out for robbers...unfortunately there is no right answer on what size works for all..you have to determine what works for YOUR hive at a particular time..