Mother Church is wise to instruct us on specific matters of great importance, such as abortion, in which we have only one choice—it is always wrong. She is also wise to give broad guidance on matters in which it is appropriate for the faithful to use some discretion; for example, she teaches us to be modest, but allows us to choose what clothes to wear.
I believe that the artistry and design of rosaries is one of those areas where faithful discretion is appropriate. I am the designer of the rosaries that you linked in your question, am a faithful Catholic, regularly seek spiritual direction, and joyfully submit myself to the Church's teaching authority—the Magisterium.
On the website, I clearly describe the twofold purpose of my shop, which is both ministry and a means to provide for my family as a stay-at-home mother of four children. I was genuinely called to the ministry of my work. From the beginning, outreach of the rosary to a younger generation has been my central aim.
As Blessed John Paul II observed in his 2002 apostolic letter, Rosarium Virginis Mariae, the rosary has been at "risk [of] being wrongly devalued, and therefore no longer taught to the younger generation."
He advises that, "If the Rosary is well presented, I am sure that young people will once more surprise adults by the way they make this prayer their own and recite it with the enthusiasm typical of their age group."
He finally charges us to "Rediscover the Rosary in the light of Scripture, in harmony with the Liturgy, and in the context of your daily lives."
My rosary designs are "well presented" and consistent with this traditional form of prayer. They also encourage young people to embrace this beautiful tradition and "confidently take up the Rosary once again."
The letter beads for personalization in my rosary designs are not used for prayer, which is clear by how they are placed in the design. Further, whether one chooses to include personalized beads within a rosary is a personal decision.
Finally, the context of this conversation illustrates that some may not be able to see the forest through the trees. The purpose of the rosary is prayer, and the purpose of prayer is to bring us closer to God the Father and Christ Jesus. Nothing about my rosary designs would act to discourage any person from praying the rosary. If, however, any one of my rosary designs encourages even one person to take up the rosary and grow in his or her prayer life, then my ministry is a great success.