You should add a separate field for item photo , not as an html tag in the description. This will help new employees be familiar with inventory items quickly.
You should create inventory categories. like nails ,tools , and so on , so the user could list items by category, ordered by no. of units or alphabetically .
Another thing , some items are used as spare parts for production machines or for cars when they are used their costs are added to indirect production costs or as car expense and so on. How your software handles that.
All your suggested additions can be done with custom fields. They are not built into the software because the program has no use for the information. But if it is useful to you, add it.
Inventory items used for internal maintenance are handled as write-offs. See the Guide: Write off inventory | Manager.
Another thing , your software uses weighted average for costing. does that mean I have to re-inter it after I purchase new units with a new price or does the software recalculates it itself.
I would advise you to always Manager as an accounting software and not as a POS or anything else. It will help you with accounting for tax purposes and even if there are many other things it can do it is not that well developed in those areas such as inventory.