Checked on my main which is a fully trained alpha (expanded alpha skillset around 20m SP every and all alpha skills trained plus a couple omega ones so a total of 23+ mil SP but ofc the omega skills are not functioning).
Market orders
The trade skill (trade category / trade skill) states:
Knowledge of the market and skill at manipulating it. Active buy/sell order limit increased by 4 per level of skill.
It is trained to level 3 which is the limit.
The market orders window states the following:
Orders Remaining: 17 out of 17 max open orders
Total in Escrow: 0 ISK (additional 0 ISK to cover)
Base Broker Fee: 2.50% of order value
Transaction Tax: 2.50% of sales value
Sell Orders Total: 0 ISK
Buy Orders Total: 0 ISK
Ask Range: limited to 5 jumps
Bid Range: limited to stations
Modification Range: limited to stations
Remote Bid Range: limited to stations
Corporation orders have no such info so I assume but just guessing that the personal limits apply to corp ones as well, though no guarantee.
Contracts
If you plan to sell (and/or post buy contracts) on the contract market you can only post one single public or private contract per character as an alpha, however if you create a corp you can post 10 public corporate contracts and up to 500 to corp mates per character, thus if you make multiple characters that join your corp, all alpha and train the related skills each of them can post 10 contracts on behalf of your corp.
The contract main page states:
Your skill level allows you to have a total of 1 outstanding personal contract at any time.
You can create 500 more contracts issued to your corporation or members of your corporation.
You can create 10 more public contracts on behalf of your corporation.
(Note: You have to transfer the items to corporate deliveries so no need for corp office, just contract all the stuff you want to sell to your currently signed in character then accept the contract on behalf of your corp, this will move all the items to corporate deliveries from where all characters with proper permissions can access and contract from.)
Here is a somewhat related article from my blog in case you are interested:
T1 battleships manufacturing
Only checked the Hyperion but according to the in-game information window for the blueprint I should be able to manufacture it.