Hi Tyson
Here some thoughts to your questions:
1) They way I understand your question you need two tables (LeadListView open to all agents & CallList rendering according to logged in agent). Set up two models (one for each table) with the same SF object but different model conditions. When an agent ADDs a lead to his/her Call List (by button?) you set the action to update a field and then requery the two models (e.g. a lookup field that is being filled with the “agent’s userid” or a checkbox “agent assigned=true”). This field can be used as the condition on both models (e.g. the Lead list view model has the condition “agent field = blank” or “checkbox = false” and the agent’s Call List has the condition “agent field = user id / not blank” or “checkbox =true”). Like that you should start to fill up your CallList but the same record should no longer be in LeadListView) with only shows unassigned Leads. Here also the URL link to the Skuid documentation on model conditions: https://docs.skuid.com/v10.0.4/en/skuid/models/conditions.html
2) They way I understand it you want two filters. One for age and one for call attempts. When filtering on age first you can go ahead and set the call attempts filter as well and also change one or the other again. It will show you all possible call attempts picklist values and when you choose a call attempt picklist value it will also keep the age filter (so you may get an empty list because no record exists with the chosen age-call attempt-picklist-value-combination). This is the standard Skuid filter functionality. If you want to make the two filters dependable it is a little trickier but also doable declaratively. Here also the URL Link to the filter documentations: https://docs.skuid.com/v10.0.4/en/skuid/filters/table-filter.html
Please let us know if you need any more help.