A pair of scissors can't be sent for 60c even if the envelope is under 5mm, presuming they are rigid, anyway.

IMHO, for the time being I would lose the store, for no reason other than the fee isn't worth it for only two listings. Without a store, you still get 40 free listings per month, meaning you can list your items as BIN every ten days and still have 34 free listings remaining, and the percentage break on FVF you get with a store wouldn't make up for it either unless you were selling more than $1000 per month (presuming you're subscribed to a basic store). If you have more product lines that can cross-promote one another, a store is much more viable. 

The only thing in your listings that has the potential to lose buyers is the bit about no responsibility for lost items - you can be made to be responsible (financially) via PayPal for any item sent unregistered etc, but even a buyer who understand that could think it would be more hassle than it's worth to try and resolve an issue that crops up. I always think, aside from the basic necessities such as payment time frames, information in listings should generally focus on the benefits of buying from you, not the drawbacks 😉 .

Almost everything I sell goes as a letter; I provide a registered option because some buyers like to use it, but most go unregistered/untracked and so far the number of lost items (plus cost to replace/refund) has been minimal to insignificant, so it remains simple enough to keep my postage costs low (which = higher sales) and issue refunds/replacements for any lost items (which is significantly better for customer relations).