It’s sound advice to contact the Office of Fair Trading (assuming you’re in NSW), but be warned, their response can differ depending upon the precise questions you ask and who you speak with.
In the meantime, here’s my response to the basic issues you raise – again assuming that your Strata Plan is in NSW:
1) Holding a General Meeting via a teleconference isn’t illegal, but it’s highly unusual as a the voting intentions of an absent Owner is customarily expressed via a Proxy (i.e. someone you know who is attending the Meeting), where you can give written instructions about how wish to vote on each Motion of the Agenda.
2) Your Owners Corporation should not allocate visitors carspaces to individual Owners as these would have been designated for “visitors” by the Local Council at the time that the Development of your Strata Plan was approved, and allocating them to individuals would breach that Approval.
If these carspaces are unallocated (i.e. not for visitors or for any Lot in particular), then they may allocated to individual Owners BUT this would require the prior agreement of at least 75% of Owners present personally or by proxy at a General Meeting followed by the Registration of an Exclusive Use By-Law and a payment to the Owners Corporation by those individual Owners of an amount ($) equivalent to the increased value of each of their properties as a consequence of the fact that they now have an allocated carspace.
3) There should either be a Special By-Law (as above) in place to permit all Owners (who want) to install air-conditioners and shutters etc to do so or a prior written consent issued to each Owner individually by the Owners Corporation including a condition that those Owners are responsible for the maintenance and repair of those “additions” (particularly the aircon). Depending upon the delegations granted to the Strata Manager, they could issue that consent on behalf of the Owners Corporation
4) This is why your Owners Corporation should have Registered a Special By-Law with conditions or issued a written prior consent with conditions to each Owner who wanted to enclose their carports, because in the absence of conditions such as one about the Owners being responsible for on-going maintenance and repairs of the additions (i.e. the doors) then the Owners Corporation becomes responsible for that maintenance as the additions are by default deemed to be Common Property.
So now that you have my comments and after you have obtained comments from the Office of Fair Trading, what are you going to do?
Well, if you really want to have the matters discussed and properly resolved, you need to “requisition” a General Meeting of the Owners Corporation. You can either ask the Secretary of your Executive Committee to do that, or if they refuse, obtain written support to do that from at least 25% of all the Owners in your Plan (like a petition). In both instances, you will need to write down the details (perhaps using the 4 points above) and give that to the Secretary, who in the latter case must then convene a General Meeting to discuss and resolve them.
I’ve deliberately omitted some of the complexities, but hopefully the totality of the advice you receive will be a start.