y axis line not shown and how to make multiple series of data appear at once

[grassland-curing-cfa]

Apologies if this is not the right place to ask questions. I am new to ApexCharts and trying to plot multiple data series (as many as 60) on one chart.

Can I get some help with these four points:

1. y axis is not shown by default. How can I make it appear?
2. There 184 data values for each data series. By default, each line becomes dashes instead of line towards the end of it. Ideally they are all consistently lines.
3. The x axis categories are of Datetime type and run from "1900-07-01" to "1900-12-31". I would like only the months to be shown as labels. How to make each label placed at the center of the segment instead of left by default?
4. When drawing many data series, ApexCharts tends to show one line at a time and it can take a dozen of seconds to draw 60 lines. How to set up all lines to appear at once?

Here is my code:

var options = {
    series: data['datasets'],
    chart: {
      width: 1200,
      type: 'line',
    },
    forecastDataPoints: {
      count: 7
    },
    stroke: {
      width: 1,
      curve: 'smooth'
    },
    xaxis: {
      type: 'datetime',
      categories: data['labels'],
      labels: {
        format: 'MMM',
        showDuplicates: false
      }
    },
    yaxis: {
      show: true,
      showAlways: false,
    },
    title: {
      text: 'Rainfall',
      align: 'center',
      style: {
        fontSize: "20px",
        color: '#666'
      }
    },
    fill: {
      type: 'gradient',
      gradient: {
        shade: 'dark',
        gradientToColors: ['#FDD835'],
        shadeIntensity: 1,
        type: 'horizontal',
        opacityFrom: 1,
        opacityTo: 1,
        stops: [0, 100, 100, 100]
      },
    },
    legend: {
      show: false
    }
  };

  var chart = new ApexCharts(document.querySelector("#chart"), options);
  chart.render();