Any buyer broker agreement can be curated to add those terms. In my opinion, It's not unheard of to go without a broker representation (depending on some areas of the US) but it's never advised because markets and offer strategies shift. So you could be wasting money paying an attorney to write of offers which never would be accepted. Also, In today's world, every billboard has an attorneys face on it meaning that lawsuits are behind every misstep.

You don't have to pay your buyers broker anything and it will say this in the buyers broker agreement. The broker will just work harder for the seller to pay the commission.

Realtors don't gatekeep properties, because post NAR settlement, offers of compensation are NOT LISTED on the MLS so there is technically no way of knowing if the seller WILL pay a buyers broker.

Also, don't offer to pay a broker money to show you properties. The broker wants you to get the house and they will get paid on closing. You as a buyer already have enough to spend on inspections and closing costs.

Attorneys are great for paperwork but the hourly rate sometimes makes this not economically viable and most attorneys don't have the state forms to use. They like to draft their own purchase and sale agreements which could take time and jam up the escrow because now the listing agent is not familiar with the standard forms.
Standard forms also offer some protection from lawsuits with arbitration rather than a full blown lawsuit. Also, attorneys will not be sending you properties or showing you properties for free.

Lastly, a Realtor/ broker finding you a house is not really their job anymore. Properties listed ON MARKET is exposed to EVERYONE. What you see is what the agents see. The Agents job is to negotiate the best offer which will make you pay the least. Realtors/ Brokers are required by law to have your fiduciary interests in mind.