This is not typical of a US-based fund. Subscription agreements and shareholder deeds are concepts that I usually see with European investors. A subscription agreement is typically like a purchase agreement in that it contains a number of reps and warranties by the company about its business, assets and financials and then states any closing conditions or other terms for the investment. Having a SAFE with a subscription agreement is virtually unheard of in the US in my experience. A share deed I think is similar to a stock certificate and is a mechanism to register the shares with the company and applicable jurisdiction - also, not typical or needed in the US.
A subscription agreement itself isn’t a harmful concept as long as the company understands that it is unusual (and probably unnecessary) for a SAFE investment. It could be harmless but they should read it carefully to make sure there are no gotchas.